Update string concatenations to use std::format

add pretty print log

tooling/pipeline/CMakeLists.txt

@@ -138,7 +138,8 @@ FetchContent_MakeAvailable(cpp-httplib)
 
 # 5. Executable & Sources
 add_executable(${PROJECT_NAME}
-        includes/services/enrichment/mock_enrichment.h)
+        includes/services/enrichment/mock_enrichment.h
+        includes/json_handling/pretty_print.h)
 
 # --- Entry point ---
 target_sources(${PROJECT_NAME} PRIVATE

tooling/pipeline/includes/data_generation/llama_generator.h

@@ -38,8 +38,7 @@ class LlamaGenerator final : public DataGenerator {
    * @param prompt_directory Directory service for loading named prompt files.
    */
   LlamaGenerator(const ApplicationOptions& options,
-                 const std::string& model_path,
+                 const std::string& model_path, std::shared_ptr<ILogger> logger,
-                 std::shared_ptr<ILogger> logger,
                  std::unique_ptr<IPromptFormatter> prompt_formatter,
                  std::unique_ptr<IPromptDirectory> prompt_directory);
 

tooling/pipeline/includes/json_handling/pretty_print.h

@@ -0,0 +1,109 @@
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_JSON_HANDLING_PRETTY_PRINT_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_JSON_HANDLING_PRETTY_PRINT_H_
+
+/**
+ * @file json_handling/pretty_print.h
+ * @brief Pretty-printing utilities for JSON values.
+ *
+ * Provides formatting capability for boost::json::value with indentation and
+ * readable output. Adapted from Boost JSON library examples.
+ */
+
+#include <boost/json.hpp>
+#include <ostream>
+#include <string>
+
+/**
+ * @brief Pretty-prints a JSON value to an output stream with indentation.
+ *
+ * Recursively formats JSON objects and arrays with consistent 4-space
+ * indentation. Adapted from:
+ * https://raw.githubusercontent.com/boostorg/json/refs/heads/develop/example/pretty.cpp
+ *
+ * @param outstream Output stream to write formatted JSON.
+ * @param json_val JSON value to format.
+ * @param indent Optional indentation string (managed internally on first call).
+ */
+inline void PrettyPrint(std::ostream& outstream,
+                        boost::json::value const& json_val,
+                        std::string* indent = nullptr) {
+  std::string str;
+  if (indent == nullptr) {
+    indent = &str;
+  }
+  switch (json_val.kind()) {
+    case boost::json::kind::object: {
+      outstream << "{\n";
+      indent->append(4, ' ');
+      auto const& obj = json_val.get_object();
+      if (!obj.empty()) {
+        const auto* iter = obj.begin();
+        for (;;) {
+          outstream << *indent << boost::json::serialize(iter->key()) << " : ";
+          PrettyPrint(outstream, iter->value(), indent);
+          iter = std::next(iter);
+          if (iter == obj.end()) {
+            break;
+          }
+
+          outstream << ",\n";
+        }
+      }
+      outstream << "\n";
+      indent->resize(indent->size() - 4);
+      outstream << *indent << "}";
+      break;
+    }
+
+    case boost::json::kind::array: {
+      outstream << "[\n";
+      indent->append(4, ' ');
+      auto const& arr = json_val.get_array();
+      if (!arr.empty()) {
+        const auto* iter = arr.begin();
+        for (;;) {
+          outstream << *indent;
+          PrettyPrint(outstream, *iter, indent);
+          iter = std::next(iter);
+          if (iter == arr.end()) {
+            break;
+          }
+          outstream << ",\n";
+        }
+      }
+      outstream << "\n";
+      indent->resize(indent->size() - 4);
+      outstream << *indent << "]";
+      break;
+    }
+
+    case boost::json::kind::string: {
+      outstream << serialize(json_val.get_string());
+      break;
+    }
+
+    case boost::json::kind::uint64:
+    case boost::json::kind::int64:
+    case boost::json::kind::double_:
+      outstream << json_val;
+      break;
+
+    case boost::json::kind::bool_:
+      if (json_val.get_bool()) {
+        outstream << "true";
+      } else {
+        outstream << "false";
+      }
+      break;
+
+    case boost::json::kind::null:
+      outstream << "null";
+      break;
+  }
+
+  if (indent->empty()) {
+    outstream << "\n";
+  }
+}
+
+#endif

tooling/pipeline/includes/services/logging/log_dispatcher.h

@@ -6,8 +6,8 @@
  * them to spdlog on a dedicated thread.
  */
 
-#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_DISPATCHER_H_
-#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_DISPATCHER_H_
 
 #include <spdlog/spdlog.h>
 
@@ -23,31 +23,31 @@
  */
 class LogDispatcher {
  public:
-   /**
+  /**
-     * @brief Construct a log dispatcher.
+   * @brief Construct a log dispatcher.
-    *
+   *
-     * @param channel Reference to the bounded channel used for log retrieval.
+   * @param channel Reference to the bounded channel used for log retrieval.
-    */
+   */
-   explicit LogDispatcher(BoundedChannel<LogEntry>& channel);
+  explicit LogDispatcher(BoundedChannel<LogEntry>& channel);
 
-   LogDispatcher(const LogDispatcher&) = delete;
+  LogDispatcher(const LogDispatcher&) = delete;
-   LogDispatcher& operator=(const LogDispatcher&) = delete;
+  LogDispatcher& operator=(const LogDispatcher&) = delete;
-   LogDispatcher(LogDispatcher&&) = delete;
+  LogDispatcher(LogDispatcher&&) = delete;
-   LogDispatcher& operator=(LogDispatcher&&) = delete;
+  LogDispatcher& operator=(LogDispatcher&&) = delete;
-   ~LogDispatcher() = default;
+  ~LogDispatcher() = default;
 
-   /**
+  /**
-     * @brief Drain the channel and forward entries to spdlog.
+   * @brief Drain the channel and forward entries to spdlog.
-    *
+   *
-     * Intended to be called once on a dedicated thread. The loop returns after
+   * Intended to be called once on a dedicated thread. The loop returns after
-     * the channel has been closed and all queued entries have been processed.
+   * the channel has been closed and all queued entries have been processed.
-    */
+   */
-   void Run();
+  void Run();
 
  private:
-   BoundedChannel<LogEntry>& channel_;
+  BoundedChannel<LogEntry>& channel_;
 
-   static spdlog::level::level_enum ToSpdlogLevel(LogLevel level);
+  static spdlog::level::level_enum ToSpdlogLevel(LogLevel level);
 };
 
-#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_DISPATCHER_H_

tooling/pipeline/src/biergarten_pipeline_orchestrator/generate_breweries.cc

@@ -3,13 +3,17 @@
  * @brief BiergartenDataGenerator::GenerateBreweries() implementation.
  */
 
-#include "services/logging/logger.h"
+#include <chrono>
+#include <format>
+
 #include "biergarten_pipeline_orchestrator.h"
+#include "services/logging/logger.h"
 
 void BiergartenPipelineOrchestrator::GenerateBreweries(
     std::span<const EnrichedCity> cities) {
-  logger_->Log(LogLevel::Info, PipelinePhase::BreweryAndBeerGeneration,
+  logger_->Log({.level = LogLevel::Info,
-               "=== SAMPLE BREWERY GENERATION ===");
+                .phase = PipelinePhase::BreweryAndBeerGeneration,
+                .message = "=== SAMPLE BREWERY GENERATION ==="});
 
   generated_breweries_.clear();
   size_t skipped_count = 0;
@@ -29,33 +33,36 @@ void BiergartenPipelineOrchestrator::GenerateBreweries(
       } catch (const std::exception& export_exception) {
         ++export_failed_count;
 
-        logger_->Log(LogLevel::Warn, PipelinePhase::BreweryAndBeerGeneration,
+        logger_->Log(
-                     std::string("[Pipeline] Generated brewery for '") +
+            {.level = LogLevel::Warn,
-                         location.city + "' (" + location.country +
+             .phase = PipelinePhase::BreweryAndBeerGeneration,
-                         ") but SQLite export failed: " +
+             .message =
-                         export_exception.what());
+                 std::format("[Pipeline] Generated brewery for '{}' ({}) but SQLite export failed: {}",
+                 location.city, location.country, export_exception.what())});
       }
     } catch (const std::exception& e) {
       ++skipped_count;
 
-      logger_->Log(LogLevel::Warn, PipelinePhase::BreweryAndBeerGeneration,
+      logger_->Log({.level = LogLevel::Warn,
-                   std::string("[Pipeline] Skipping city '") + location.city +
+                    .phase = PipelinePhase::BreweryAndBeerGeneration,
-                       " (" + location.country + "): brewery generation failed: " +
+                    .message = std::format("[Pipeline] Skipping city '{}' ({}): brewery generation failed: {}",
-                       e.what());
+                               location.city, location.country, e.what())});
     }
   }
 
   if (skipped_count > 0) {
-    logger_->Log(LogLevel::Warn, PipelinePhase::BreweryAndBeerGeneration,
+    logger_->Log({.level = LogLevel::Warn,
-                 std::string("[Pipeline] Skipped ") +
+                  .phase = PipelinePhase::BreweryAndBeerGeneration,
-                     std::to_string(skipped_count) +
+                  .message = std::format(
-                     " city/cities due to generation errors");
+                      "[Pipeline] Skipped {} city/cities due to generation errors",
+                      skipped_count)});
   }
 
   if (export_failed_count > 0) {
-    logger_->Log(LogLevel::Warn, PipelinePhase::Teardown,
+    logger_->Log({.level = LogLevel::Warn,
-                 std::string("[Pipeline] Failed to export ") +
+                  .phase = PipelinePhase::Teardown,
-                     std::to_string(export_failed_count) +
+                  .message = std::format(
-                     " generated brewery/breweries to SQLite");
+                      "[Pipeline] Failed to export {} generated brewery/breweries to SQLite",
+                      export_failed_count)});
   }
 }

tooling/pipeline/src/biergarten_pipeline_orchestrator/log_results.cc

@@ -3,29 +3,35 @@
  * @brief BiergartenDataGenerator::LogResults() implementation.
  */
 
-#include "services/logging/logger.h"
+#include <boost/json/array.hpp>
+#include <chrono>
+#include <format>
 
+#include "../../includes/json_handling/pretty_print.h"
 #include "biergarten_pipeline_orchestrator.h"
-#include <sstream>
+#include "services/logging/logger.h"
-
 void BiergartenPipelineOrchestrator::LogResults() const {
-  std::ostringstream msg;
+  boost::json::array output;
-  msg << "GENERATED DATA DUMP\n";
-  size_t index = 1;
-  for (const auto& [location, brewery] : generated_breweries_) {
-    msg << index << ". city=\"" << location.city << "\" country=\""
-        << location.country << "\" state=\"" << location.state_province
-        << "\" iso3166_2=" << location.iso3166_2 << " lat="
-        << location.latitude << " lon=" << location.longitude << "\n";
 
-    msg << "   brewery_name_en=\"" << brewery.name_en << "\"\n";
+  for (const auto& [location, brewery] : generated_breweries_) {
-    msg << "   brewery_description_en=\"" << brewery.description_en
+    output.push_back(boost::json::object{
-        << "\"\n";
+        {"name_en", brewery.name_en},
-    msg << "   brewery_name_local=\"" << brewery.name_local << "\"\n";
+        {"description_en", brewery.description_en},
-    msg << "   brewery_description_local=\"" << brewery.description_local
+        {"name_local", brewery.name_local},
-        << "\"\n";
+        {"description_local", brewery.description_local},
-    ++index;
+        {"location", boost::json::object{
+                         {"city", location.city},
+                         {"country", location.country},
+                         {"state_province", location.state_province},
+                         {"iso3166_2", location.iso3166_2},
+                         {"latitude", location.latitude},
+                         {"longitude", location.longitude},
+                     }}});
   }
 
-  logger_->Log(LogLevel::Debug, PipelinePhase::Teardown, msg.str());
+  std::ostringstream oss;
+  PrettyPrint(oss, output);
+  logger_->Log({.level = LogLevel::Info,
+                .phase = PipelinePhase::Teardown,
+                .message = oss.str()});
 }

tooling/pipeline/src/biergarten_pipeline_orchestrator/query_cities_with_countries.cc

@@ -3,9 +3,8 @@
  * @brief BiergartenDataGenerator::QueryCitiesWithCountries() implementation.
  */
 
-#include "services/logging/logger.h"
-
 #include <algorithm>
+#include <chrono>
 #include <filesystem>
 #include <format>
 #include <iterator>
@@ -13,16 +12,18 @@
 
 #include "biergarten_pipeline_orchestrator.h"
 #include "json_handling/json_loader.h"
+#include "services/logging/logger.h"
 
-std::vector<Location> BiergartenPipelineOrchestrator::QueryCitiesWithCountries() {
+std::vector<Location>
-  logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+BiergartenPipelineOrchestrator::QueryCitiesWithCountries() {
-               "=== GEOGRAPHIC DATA OVERVIEW ===");
+  logger_->Log({.level = LogLevel::Info,
+                .phase = PipelinePhase::Startup,
+                .message = "=== GEOGRAPHIC DATA OVERVIEW ==="});
 
   const std::filesystem::path locations_path = "locations.json";
 
   auto all_locations = JsonLoader::LoadLocations(locations_path, logger_);
 
-
   const size_t sample_count = std::min(
       static_cast<size_t>(application_options_.pipeline.location_count),
       all_locations.size());
@@ -38,9 +39,13 @@ std::vector<Location> BiergartenPipelineOrchestrator::QueryCitiesWithCountries()
   std::ranges::sample(all_locations, std::back_inserter(sampled_locations),
                       sample_count_signed, random_generator);
 
-  logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+  logger_->Log({.level = LogLevel::Info,
-               std::format("  Locations available: {}", all_locations.size()));
+                .phase = PipelinePhase::Startup,
-  logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+                .message = std::format("  Locations available: {}",
-               std::format("  Sampled locations: {}", sampled_locations.size()));
+                                       all_locations.size())});
+  logger_->Log({.level = LogLevel::Info,
+                .phase = PipelinePhase::Startup,
+                .message = std::format("  Sampled locations: {}",
+                                       sampled_locations.size())});
   return sampled_locations;
 }

tooling/pipeline/src/biergarten_pipeline_orchestrator/run.cc

@@ -3,11 +3,12 @@
  * @brief BiergartenDataGenerator::Run() implementation.
  */
 
-#include "services/logging/logger.h"
+#include <chrono>
-
+#include <format>
 #include <utility>
 
 #include "biergarten_pipeline_orchestrator.h"
+#include "services/logging/logger.h"
 
 bool BiergartenPipelineOrchestrator::Run() {
   try {
@@ -30,18 +31,21 @@ bool BiergartenPipelineOrchestrator::Run() {
                          .region_context = std::move(region_context)});
       } catch (const std::exception& exception) {
         ++skipped_count;
-        logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+        logger_->Log(
-                     std::string("[Pipeline] Skipping city '") + city.city +
+            {.level = LogLevel::Warn,
-                         " (" + city.country + "): context lookup failed: " +
+             .phase = PipelinePhase::UserGeneration,
-                         exception.what());
+             .message = std::format(
+                 "[Pipeline] Skipping city '{}' ({}): context lookup failed: {}",
+                 city.city, city.country, exception.what())});
       }
     }
 
     if (skipped_count > 0) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log({.level = LogLevel::Warn,
-                   std::string("[Pipeline] Skipped ") +
+                    .phase = PipelinePhase::UserGeneration,
-                       std::to_string(skipped_count) +
+                    .message = std::format(
-                       " city/cities due to context lookup errors");
+                        "[Pipeline] Skipped {} city/cities due to context lookup errors",
+                        skipped_count)});
     }
 
     this->GenerateBreweries(enriched);
@@ -49,9 +53,11 @@ bool BiergartenPipelineOrchestrator::Run() {
     this->LogResults();
     return true;
   } catch (const std::exception& e) {
-    logger_->Log(LogLevel::Error, PipelinePhase::Teardown,
+    logger_->Log(
-                 std::string("Pipeline execution failed with error: ") +
+        {.level = LogLevel::Error,
-                     e.what());
+         .phase = PipelinePhase::Teardown,
+         .message =
+             std::format("Pipeline execution failed with error: {}", e.what())});
     return false;
   }
 }

tooling/pipeline/src/data_generation/llama/generate_brewery.cc

@@ -4,6 +4,7 @@
  * inference, and validates structured JSON output for brewery records.
  */
 
+#include <chrono>
 #include <format>
 #include <optional>
 #include <stdexcept>
@@ -99,9 +100,11 @@ BreweryResult LlamaGenerator::GenerateBrewery(
     raw = this->Infer(system_prompt, user_prompt, max_tokens,
                       kBreweryJsonGrammar);
     if (logger_) {
-      logger_->Log(LogLevel::Debug, PipelinePhase::BreweryAndBeerGeneration,
+      logger_->Log(
-                   std::string("LlamaGenerator: raw output (attempt ") +
+          {.level = LogLevel::Debug,
-                       std::to_string(attempt + 1) + "): " + raw);
+           .phase = PipelinePhase::BreweryAndBeerGeneration,
+           .message = std::format("LlamaGenerator: raw output (attempt {}): {}",
+                      attempt + 1, raw)});
     }
 
     // Validate output: parse JSON and check required fields
@@ -114,10 +117,11 @@ BreweryResult LlamaGenerator::GenerateBrewery(
       // Success: return parsed brewery data
 
       if (logger_) {
-        logger_->Log(LogLevel::Info, PipelinePhase::BreweryAndBeerGeneration,
+        logger_->Log(
-                     std::string(
+            {.level = LogLevel::Info,
-                         "LlamaGenerator: successfully generated brewery data on attempt ") +
+             .phase = PipelinePhase::BreweryAndBeerGeneration,
-                         std::to_string(attempt + 1));
+             .message = std::format("LlamaGenerator: successfully generated brewery data on attempt {}",
+                        attempt + 1)});
       }
 
       return brewery;
@@ -127,9 +131,12 @@ BreweryResult LlamaGenerator::GenerateBrewery(
 
     last_error = *validation_error;
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::BreweryAndBeerGeneration,
+      logger_->Log(
-                   std::string("LlamaGenerator: malformed brewery JSON (attempt ") +
+          {.level = LogLevel::Warn,
-                       std::to_string(attempt + 1) + "): " + *validation_error);
+           .phase = PipelinePhase::BreweryAndBeerGeneration,
+           .message =
+               std::format("LlamaGenerator: malformed brewery JSON (attempt {}): {}",
+               attempt + 1, *validation_error)});
     }
 
     // Update prompt with error details to guide LLM toward correct output.
@@ -148,10 +155,12 @@ BreweryResult LlamaGenerator::GenerateBrewery(
 
   // All retry attempts exhausted: log failure and throw exception
   if (logger_) {
-    logger_->Log(LogLevel::Error, PipelinePhase::BreweryAndBeerGeneration,
+    logger_->Log(
-                 std::string("LlamaGenerator: malformed brewery response after ") +
+        {.level = LogLevel::Error,
-                     std::to_string(max_attempts) + " attempts: " +
+         .phase = PipelinePhase::BreweryAndBeerGeneration,
-                     (last_error.empty() ? raw : last_error));
+       .message = std::format(
+         "LlamaGenerator: malformed brewery response after {} attempts: {}",
+         max_attempts, last_error.empty() ? raw : last_error)});
   }
   throw std::runtime_error("LlamaGenerator: malformed brewery response");
 }

tooling/pipeline/src/data_generation/llama/generate_user.cc

@@ -5,6 +5,7 @@
  */
 
 
+#include <format>
 #include <string>
 
 #include "data_generation/llama_generator.h"
@@ -19,5 +20,5 @@
 // 4. Return locale-aware username and biography
 UserResult LlamaGenerator::GenerateUser(const std::string& locale) {
   return {.username = "test_user",
-          .bio = "This is a test user profile from " + locale + "."};
+          .bio = std::format("This is a test user profile from {}.", locale)};
 }

tooling/pipeline/src/data_generation/llama/helpers.cc

@@ -16,11 +16,11 @@
 
 #include "data_generation/llama_generator_helpers.h"
 #include "llama.h"
-
+namespace {
 /**
  * String trimming: removes leading and trailing whitespace
  */
-static std::string Trim(std::string_view value) {
+std::string Trim(std::string_view value) {
   constexpr std::string_view whitespace = " \t\n\r\f\v";
   const size_t first_index = value.find_first_not_of(whitespace);
   if (first_index == std::string_view::npos) {
@@ -35,7 +35,7 @@ static std::string Trim(std::string_view value) {
  * Normalize whitespace: collapses multiple spaces/tabs/newlines into single
  * spaces
  */
-static std::string CondenseWhitespace(std::string_view text) {
+std::string CondenseWhitespace(std::string_view text) {
   std::string out;
   out.reserve(text.size());
 
@@ -61,7 +61,37 @@ static std::string CondenseWhitespace(std::string_view text) {
 // Guard against truncating in the first half of the string.
 // This preserves the critical opening content and avoids cutting critical
 // context words early in the region description.
-static constexpr size_t kTruncationGuardDivisor = 2;
+constexpr size_t kTruncationGuardDivisor = 2;
+
+bool ReadRequiredTrimmedStringField(const boost::json::object& obj,
+                                    std::string_view key, std::string& out,
+                                    std::string* error_out) {
+  const boost::json::value* field = obj.if_contains(key);
+  if (field == nullptr || !field->is_string()) {
+    return false;
+  }
+
+  const auto& string_value = field->as_string();
+  out = Trim(std::string_view(string_value.data(), string_value.size()));
+  return !out.empty();
+}
+
+bool HasSchemaPlaceholder(const std::array<std::string*, 4>& values) {
+  for (const std::string* value : values) {
+    std::string lowered = *value;
+    std::ranges::transform(lowered, lowered.begin(),
+                           [](const unsigned char character) {
+                             return static_cast<char>(std::tolower(character));
+                           });
+
+    if (lowered == "string") {
+      return true;
+    }
+  }
+
+  return false;
+}
+}  // namespace
 
 /**
  * Truncate region context to fit within max length while preserving word
@@ -121,47 +151,6 @@ void AppendTokenPiece(const llama_vocab* vocab, llama_token token,
       "LlamaGenerator: failed to decode sampled token piece");
 }
 
-static bool ReadRequiredTrimmedStringField(const boost::json::object& obj,
-                                           std::string_view key,
-                                           std::string& out,
-                                           std::string* error_out) {
-  const boost::json::value* field = obj.if_contains(key);
-  if (field == nullptr || !field->is_string()) {
-    if (error_out != nullptr) {
-      *error_out =
-          "JSON field '" + std::string(key) + "' is missing or not a string";
-    }
-    return false;
-  }
-
-  const auto& string_value = field->as_string();
-  out = Trim(std::string_view(string_value.data(), string_value.size()));
-  if (out.empty()) {
-    if (error_out != nullptr) {
-      *error_out = "JSON field '" + std::string(key) + "' must not be empty";
-    }
-    return false;
-  }
-
-  return true;
-}
-
-static bool HasSchemaPlaceholder(const std::array<std::string*, 4>& values) {
-  for (const std::string* value : values) {
-    std::string lowered = *value;
-    std::ranges::transform(lowered, lowered.begin(),
-                           [](unsigned char character) {
-                             return static_cast<char>(std::tolower(character));
-                           });
-
-    if (lowered == "string") {
-      return true;
-    }
-  }
-
-  return false;
-}
-
 std::optional<std::string> ValidateBreweryJson(const std::string& raw,
                                                BreweryResult& brewery_out) {
   boost::system::error_code error_code;
@@ -209,7 +198,7 @@ std::optional<std::string> ValidateBreweryJson(const std::string& raw,
     return validation_error;
   }
 
-  const std::array<std::string*, 4> schema_placeholders = {
+  const std::array schema_placeholders = {
       &brewery_out.name_en, &brewery_out.description_en,
       &brewery_out.name_local, &brewery_out.description_local};
   if (HasSchemaPlaceholder(schema_placeholders)) {

tooling/pipeline/src/data_generation/llama/infer.cc

@@ -6,6 +6,8 @@
  */
 
 #include <algorithm>
+#include <chrono>
+#include <format>
 #include <memory>
 #include <stdexcept>
 #include <string>
@@ -105,7 +107,7 @@ std::string LlamaGenerator::InferFormatted(const std::string& formatted_prompt,
       .top_p = sampling_top_p_,
       .seed = static_cast<uint32_t>(rng_()),
   };
-  auto sampler = MakeSamplerChain(vocab, sampler_config, grammar);
+  const auto sampler = MakeSamplerChain(vocab, sampler_config, grammar);
 
   /**
    * Clear KV cache to ensure clean inference state (no residual context)
@@ -170,12 +172,12 @@ std::string LlamaGenerator::InferFormatted(const std::string& formatted_prompt,
   prompt_tokens.resize(static_cast<size_t>(token_count));
   if (token_count > prompt_budget) {
     if (logger_) {
-      logger_->Log(
+      logger_->Log({.level = LogLevel::Warn,
-          LogLevel::Warn, PipelinePhase::BreweryAndBeerGeneration,
+                    .phase = PipelinePhase::BreweryAndBeerGeneration,
-          std::string("LlamaGenerator: prompt too long (") +
+                    .message = std::format(
-              std::to_string(token_count) + ") tokens, truncating to " +
+                        "LlamaGenerator: prompt too long ({} tokens), "
-              std::to_string(prompt_budget) +
+                        "truncating to {} tokens to fit n_batch/n_ctx limits",
-              " tokens to fit n_batch/n_ctx limits");
+                        token_count, prompt_budget)});
     }
     prompt_tokens.resize(static_cast<size_t>(prompt_budget));
     token_count = prompt_budget;

tooling/pipeline/src/data_generation/llama/load.cc

@@ -5,6 +5,7 @@
  */
 
 #include <algorithm>
+#include <chrono>
 #include <stdexcept>
 #include <string>
 #include <utility>
@@ -27,8 +28,10 @@ void LlamaGenerator::Load(const std::string& model_path) {
 
   llama_model_params model_params = llama_model_default_params();
   model_params.n_gpu_layers = n_gpu_layers_;
-  LlamaGenerator::ModelHandle loaded_model(
+
+  ModelHandle loaded_model(
       llama_model_load_from_file(model_path.c_str(), model_params));
+
   if (!loaded_model) {
     throw std::runtime_error(
         "LlamaGenerator: failed to load model from path: " + model_path);
@@ -38,8 +41,9 @@ void LlamaGenerator::Load(const std::string& model_path) {
   context_params.n_ctx = n_ctx_;
   context_params.n_batch = std::min(n_ctx_, kMaxBatchSize);
 
-  LlamaGenerator::ContextHandle loaded_context(
+  ContextHandle loaded_context(
       llama_init_from_model(loaded_model.get(), context_params));
+
   if (!loaded_context) {
     throw std::runtime_error("LlamaGenerator: failed to create context");
   }
@@ -48,7 +52,9 @@ void LlamaGenerator::Load(const std::string& model_path) {
   context_ = std::move(loaded_context);
 
   if (logger_) {
-    logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+    logger_->Log({.level = LogLevel::Info,
-                 std::string("[LlamaGenerator] Loaded model: ") + model_path);
+                  .phase = PipelinePhase::Startup,
+                  .message = std::format("[LlamaGenerator] Loaded model: {} ",
+                                         model_path)});
   }
 }

tooling/pipeline/src/json_handling/json_loader.cc

@@ -6,6 +6,7 @@
 
 #include "json_handling/json_loader.h"
 
+#include <format>
 #include "services/logging/logger.h"
 #include <iostream>
 
@@ -20,8 +21,8 @@ static std::string ReadRequiredString(const boost::json::object& object,
                                       const char* key) {
   const boost::json::value* value = object.if_contains(key);
   if (value == nullptr || !value->is_string()) {
-    throw std::runtime_error(std::string("Missing or invalid string field: ") +
+    throw std::runtime_error(
-                             key);
+        std::format("Missing or invalid string field: {}", key));
   }
   const std::string_view text = value->as_string();
   return std::string(text);
@@ -31,8 +32,8 @@ static double ReadRequiredNumber(const boost::json::object& object,
                                  const char* key) {
   const boost::json::value* value = object.if_contains(key);
   if (value == nullptr || !value->is_number()) {
-    throw std::runtime_error(std::string("Missing or invalid numeric field: ") +
+    throw std::runtime_error(
-                             key);
+        std::format("Missing or invalid numeric field: {}", key));
   }
   return value->to_number<double>();
 }
@@ -42,7 +43,7 @@ static std::vector<std::string> ReadRequiredStringArray(
   const boost::json::value* value = object.if_contains(key);
   if (value == nullptr || !value->is_array()) {
     throw std::runtime_error(
-        std::string("Missing or invalid string array field: ") + key);
+      std::format("Missing or invalid string array field: {}", key));
   }
 
   const auto& array = value->as_array();
@@ -51,7 +52,7 @@ static std::vector<std::string> ReadRequiredStringArray(
   for (const auto& item : array) {
     if (!item.is_string()) {
       throw std::runtime_error(
-          std::string("Missing or invalid string array field: ") + key);
+          std::format("Missing or invalid string array field: {}", key));
     }
     items.emplace_back(item.as_string());
   }

tooling/pipeline/src/main.cc

@@ -4,12 +4,15 @@
  * initializes shared infrastructure, and executes the pipeline entry flow.
  */
 
-#include <spdlog/spdlog.h>
 #include <spdlog/fmt/fmt.h>
+#include <spdlog/spdlog.h>
 
 #include <boost/di.hpp>
 #include <boost/program_options.hpp>
+#include <chrono>
 #include <exception>
+#include <format>
+#include <iostream>
 #include <memory>
 #include <optional>
 #include <string>
@@ -43,12 +46,13 @@ int main(const int argc, char** argv) {
   spdlog::set_level(spdlog::level::debug);
   spdlog::set_pattern("│ %Y-%m-%d %H:%M:%S.%e │ %^%-7l%$ │ %v");
   BoundedChannel<LogEntry> log_channel(kLogMaxCount);
-  auto log_dispatcher = std::make_unique<LogDispatcher>(log_channel);
-  std::thread log_thread([&log_dispatcher] { log_dispatcher->Run(); });
 
+  auto log_dispatcher =  //
+      std::make_unique<LogDispatcher>(log_channel);
   std::shared_ptr<ILogger> log_producer =
       std::make_shared<LogProducer>(log_channel);
 
+  std::thread log_thread([&log_dispatcher] { log_dispatcher->Run(); });
   auto shutdown = [&](const int exit_code) {
     log_channel.Close();
     log_thread.join();
@@ -62,18 +66,21 @@ int main(const int argc, char** argv) {
     const LlamaBackendState llama_backend_state;
 #endif
 
-    log_producer->Log(LogLevel::Info, PipelinePhase::Startup, "STARTING PIPELINE");
+    log_producer->Log({.level = LogLevel::Info,
+                       .phase = PipelinePhase::Startup,
+                       .message = "STARTING PIPELINE"});
 
     const std::optional<ApplicationOptions> parsed_options =
         ParseArguments(argc, argv, log_producer);
 
     if (!parsed_options.has_value()) {
-      return shutdown(0);
+      return shutdown(EXIT_FAILURE);
     }
 
     const auto options = *parsed_options;
     const std::string model_path = options.generator.model_path.string();
-    const auto sampling = options.generator.sampling.value_or(SamplingOptions{});
+    const auto sampling =
+        options.generator.sampling.value_or(SamplingOptions{});
 
     std::unique_ptr<IPromptDirectory> prompt_directory;
 
@@ -82,9 +89,12 @@ int main(const int argc, char** argv) {
         prompt_directory = std::make_unique<PromptDirectory>(
             options.pipeline.prompt_dir, log_producer);
       } catch (const std::exception& dir_error) {
-        log_producer->Log(LogLevel::Error, PipelinePhase::Startup,
+        log_producer->Log({.level = LogLevel::Error,
-                          fmt::format("Invalid --prompt-dir: {}", dir_error.what()));
+                           .phase = PipelinePhase::Startup,
-        return shutdown(1);
+                           .message = std::format("Invalid --prompt-dir: {}",
+                                                  dir_error.what())});
+
+        return shutdown(EXIT_FAILURE);
       }
     }
 
@@ -93,26 +103,39 @@ int main(const int argc, char** argv) {
         di::bind<ApplicationOptions>().to(options),
         di::bind<std::string>().to(model_path),
         di::bind<IExportService>().to<SqliteExportService>(),
-        di::bind<IPromptFormatter>().to(
+        di::bind<IPromptFormatter>().to([options, log_producer] {
-            [options, log_producer] {
+          if (options.generator.use_mocked) {
-              if (options.generator.use_mocked) {
+            {
-                log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+              log_producer->Log(
-                                  "Prompt formatter: none (mock mode)");
+                  {.level = LogLevel::Info,
-                return std::unique_ptr<IPromptFormatter>(nullptr);
+                   .phase = PipelinePhase::Startup,
-              }
+                   .message = "Prompt formatter: none (mock mode)"});
-              log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+            }
-                                "Prompt formatter: Gemma4JinjaPromptFormatter");
+            return std::unique_ptr<IPromptFormatter>(nullptr);
-              return std::unique_ptr<IPromptFormatter>(
+          }
-                  std::make_unique<Gemma4JinjaPromptFormatter>());
+          {
-            }),
+            log_producer->Log(
+                {.level = LogLevel::Info,
+                 .phase = PipelinePhase::Startup,
+                 .message = "Prompt formatter: Gemma4JinjaPromptFormatter"});
+          }
+          return std::unique_ptr<IPromptFormatter>(
+              std::make_unique<Gemma4JinjaPromptFormatter>());
+        }),
         di::bind<WebClient>().to([options, log_producer] {
           if (options.generator.use_mocked) {
-            log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+            {
-                              "Web client: none (mock mode)");
+              log_producer->Log({.level = LogLevel::Info,
+                                 .phase = PipelinePhase::Startup,
+                                 .message = "Web client: none (mock mode)"});
+            }
             return std::unique_ptr<WebClient>(nullptr);
           }
-          log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+          {
-                            "Web client: HttpWebClient");
+            log_producer->Log({.level = LogLevel::Info,
+                               .phase = PipelinePhase::Startup,
+                               .message = "Web client: HttpWebClient"});
+          }
           return std::unique_ptr<WebClient>(
               std::make_unique<HttpWebClient>(log_producer));
         }),
@@ -120,12 +143,18 @@ int main(const int argc, char** argv) {
             [options, &log_producer](
                 const auto& inj) -> std::unique_ptr<IEnrichmentService> {
               if (options.generator.use_mocked) {
-                log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+                {
-                                  "Enrichment: mock");
+                  log_producer->Log({.level = LogLevel::Info,
+                                     .phase = PipelinePhase::Startup,
+                                     .message = "Enrichment: mock"});
+                }
                 return std::make_unique<MockEnrichmentService>();
               }
-              log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+              {
-                                "Enrichment: Wikipedia");
+                log_producer->Log({.level = LogLevel::Info,
+                                   .phase = PipelinePhase::Startup,
+                                   .message = "Enrichment: Wikipedia"});
+              }
               return std::make_unique<WikipediaEnrichmentService>(
                   inj.template create<std::unique_ptr<WebClient>>(),
                   log_producer);
@@ -134,20 +163,23 @@ int main(const int argc, char** argv) {
             [&options, &model_path, &sampling, &prompt_directory,
              &log_producer](const auto& inj) -> std::unique_ptr<DataGenerator> {
               if (options.generator.use_mocked) {
-                log_producer->Log(LogLevel::Info, PipelinePhase::Startup,
+                {
-                                  "Generator: mock");
+                  log_producer->Log({.level = LogLevel::Info,
+                                     .phase = PipelinePhase::Startup,
+                                     .message = "Generator: mock"});
+                }
                 return std::make_unique<MockGenerator>();
               }
-              log_producer->Log(
+              {
-                  LogLevel::Info, PipelinePhase::Startup,
+                log_producer->Log(
-                  fmt::format(
+                    {.level = LogLevel::Info,
-                      "Generator: LlamaGenerator | model={} | temp={:.2f} top_p={:.2f} top_k={} n_ctx={} seed={}",
+                     .phase = PipelinePhase::Startup,
-                      model_path,
+                     .message = std::format(
-                      sampling.temperature,
+                         "Generator: LlamaGenerator | model={} | temp={:.2f} "
-                      sampling.top_p,
+                         "top_p={:.2f} top_k={} n_ctx={} seed={}",
-                      sampling.top_k,
+                         model_path, sampling.temperature, sampling.top_p,
-                      sampling.n_ctx,
+                         sampling.top_k, sampling.n_ctx, sampling.seed)});
-                      sampling.seed));
+              }
               return std::make_unique<LlamaGenerator>(
                   options, model_path, log_producer,
                   inj.template create<std::unique_ptr<IPromptFormatter>>(),
@@ -158,21 +190,29 @@ int main(const int argc, char** argv) {
         injector.create<std::unique_ptr<BiergartenPipelineOrchestrator>>();
 
     if (!orchestrator->Run()) {
-      log_producer->Log(LogLevel::Error, PipelinePhase::Teardown,
+      log_producer->Log({.level = LogLevel::Error,
-                        "Pipeline execution failed");
+                         .phase = PipelinePhase::Teardown,
-      return shutdown(1);
+                         .message = "Pipeline execution failed"});
+      return shutdown(EXIT_FAILURE);
     }
 
-    log_producer->Log(LogLevel::Info, PipelinePhase::Teardown,
+    log_producer->Log({.level = LogLevel::Info,
-                      fmt::format("Pipeline complete in {} ms", timer.Elapsed()));
+                       .phase = PipelinePhase::Teardown,
+                       .message = std::format("Pipeline complete in {} ms",
+                                              timer.Elapsed())});
 
-    return shutdown(0);
+    return shutdown(EXIT_SUCCESS);
 
   } catch (const std::exception& exception) {
+    const LogEntry log_entry{.level = LogLevel::Error,
+                             .phase = PipelinePhase::Teardown,
+                             .message = exception.what()};
     if (log_producer) {
-      log_producer->Log(LogLevel::Error, PipelinePhase::Teardown,
+      log_producer->Log(log_entry);
-                        fmt::format("Unhandled fatal error: {}", exception.what()));
+    } else {
+      std::cerr << log_entry.message << std::endl;
     }
-    return shutdown(1);
+
+    return shutdown(EXIT_FAILURE);
   }
 }

tooling/pipeline/src/services/enrichment/wikipedia/fetch_extract.cc

@@ -14,15 +14,15 @@
 using namespace boost;
 
 std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
-
   const std::string cache_key(query);
 
   // 1. Cache Lookup
   if (const auto cache_it = this->extract_cache_.find(cache_key);
       cache_it != this->extract_cache_.end()) {
     if (logger_) {
-      logger_->Log(LogLevel::Debug, PipelinePhase::UserGeneration,
+      logger_->Log({.level = LogLevel::Debug,
-                   std::string("Wikipedia: Cache hit for ") + cache_key + "!");
+                    .phase = PipelinePhase::UserGeneration,
+                    .message = std::format("Wikipedia: Cache hit for {}!", cache_key)});
     }
     return cache_it->second;
   }
@@ -33,7 +33,6 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
       "api.php?action=query&titles={}&prop=extracts&explaintext=1&format=json",
       encoded);
 
-
   const std::string body = this->client_->Get(url);
   {
     using namespace std::literals::chrono_literals;
@@ -46,9 +45,11 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
 
   if (ec) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: JSON parse error for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "': " + ec.message());
+           .phase = PipelinePhase::UserGeneration,
+           .message = std::format("WikipediaService: JSON parse error for '{}': {}",
+                      std::string(query), ec.message())});
     }
     return {};
   }
@@ -57,9 +58,12 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
   const json::object* obj = doc.if_object();
   if (obj == nullptr) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: Expected root object for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "'");
+           .phase = PipelinePhase::UserGeneration,
+           .message =
+               std::format("WikipediaService: Expected root object for '{}'",
+               std::string(query))});
     }
     return {};
   }
@@ -72,9 +76,12 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
 
   if ((pages_ptr == nullptr) || !pages_ptr->is_object()) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: Missing query.pages for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "'");
+           .phase = PipelinePhase::UserGeneration,
+           .message =
+               std::format("WikipediaService: Missing query.pages for '{}'",
+               std::string(query))});
     }
     return {};
   }
@@ -83,9 +90,11 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
 
   if (pages.empty()) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: No pages returned for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "'");
+           .phase = PipelinePhase::UserGeneration,
+           .message = std::format("WikipediaService: No pages returned for '{}'",
+                      std::string(query))});
     }
     this->extract_cache_.emplace(cache_key, "");
     return {};
@@ -97,9 +106,12 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
 
   if (!page_val.is_object()) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: Unexpected page format for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "'");
+           .phase = PipelinePhase::UserGeneration,
+           .message =
+               std::format("WikipediaService: Unexpected page format for '{}'",
+               std::string(query))});
     }
     return {};
   }
@@ -109,9 +121,10 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
   // Handle 404/Missing status
   if (page.contains("missing")) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log({.level = LogLevel::Warn,
-                   std::string("WikipediaService: Page '") + std::string(query) +
+                    .phase = PipelinePhase::UserGeneration,
-                       "' does not exist");
+                    .message = std::format("WikipediaService: Page '{}' does not exist",
+                               std::string(query))});
     }
     this->extract_cache_.emplace(cache_key, "");
     return {};
@@ -121,9 +134,12 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
 
   if ((extract_ptr == nullptr) || !extract_ptr->is_string()) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService: No extract string found for '") +
+          {.level = LogLevel::Warn,
-                       std::string(query) + "'");
+           .phase = PipelinePhase::UserGeneration,
+           .message =
+               std::format("WikipediaService: No extract string found for '{}'",
+               std::string(query))});
     }
     this->extract_cache_.emplace(cache_key, "");
     return {};
@@ -132,10 +148,10 @@ std::string WikipediaEnrichmentService::FetchExtract(std::string_view query) {
   // 4. Success
   std::string extract(extract_ptr->as_string());
   if (logger_) {
-    logger_->Log(LogLevel::Info, PipelinePhase::UserGeneration,
+    logger_->Log({.level = LogLevel::Info,
-                 std::string("WikipediaService: Fetched ") +
+                  .phase = PipelinePhase::UserGeneration,
-                     std::to_string(extract.size()) + " chars for '" +
+                  .message = std::format("WikipediaService: Fetched {} chars for '{}'",
-                     std::string(query) + "'");
+                             extract.size(), std::string(query))});
   }
 
   this->extract_cache_.insert_or_assign(cache_key, extract);

tooling/pipeline/src/services/enrichment/wikipedia/get_summary.cc

@@ -10,12 +10,14 @@
 
 #include "services/enrichment/wikipedia_service.h"
 
-std::string WikipediaEnrichmentService::GetLocationContext(const Location& loc) {
+std::string WikipediaEnrichmentService::GetLocationContext(
+    const Location& loc) {
   using namespace std::literals::chrono_literals;
   if (!this->client_) {
     if (logger_) {
-      logger_->Log(LogLevel::Warn, PipelinePhase::UserGeneration,
+      logger_->Log({.level = LogLevel::Warn,
-                   "Wikipedia client is nullptr.");
+                    .phase = PipelinePhase::UserGeneration,
+                    .message = "Wikipedia client is nullptr."});
     }
     return {};
   }
@@ -48,17 +50,20 @@ std::string WikipediaEnrichmentService::GetLocationContext(const Location& loc)
     append_extract(FetchExtract(brewing_query));
     append_extract(FetchExtract(beer_query));
     if (logger_) {
-      logger_->Log(LogLevel::Info, PipelinePhase::UserGeneration,
+      logger_->Log({.level = LogLevel::Info,
-                   std::string("Done fetching for ") + location_query +
+                    .phase = PipelinePhase::UserGeneration,
-                       ". Sleeping for 10 seconds.");
+                    .message = std::format("Done fetching for {}. Sleeping for 10 seconds.",
+                               location_query)});
     }
     std::this_thread::sleep_for(10s);
 
   } catch (const std::runtime_error& e) {
     if (logger_) {
-      logger_->Log(LogLevel::Debug, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("WikipediaService lookup failed for '") +
+          {.level = LogLevel::Debug,
-                       location_query + "': " + e.what());
+           .phase = PipelinePhase::UserGeneration,
+           .message = std::format("WikipediaService lookup failed for '{}': {}",
+                      location_query, e.what())});
     }
   }
   return result;

tooling/pipeline/src/services/logging/log_producer.cc

@@ -16,10 +16,4 @@
 LogProducer::LogProducer(BoundedChannel<LogEntry>& channel)
     : channel_(channel) {}
 
-void LogProducer::Log(LogLevel level, PipelinePhase phase,
+void LogProducer::Log(const LogEntry& entry) { channel_.Send(entry); }
-                      const std::string_view message) {
-  channel_.Send(LogEntry{.timestamp = std::chrono::system_clock::now(),
-                         .level = level,
-                         .phase = phase,
-                         .message = std::string(message)});
-}

tooling/pipeline/src/services/prompt_directory.cc

@@ -6,7 +6,9 @@
 
 #include "services/prompting/prompt_directory.h"
 
+#include <chrono>
 #include <filesystem>
+#include <format>
 #include <fstream>
 #include <stdexcept>
 #include <string>
@@ -43,14 +45,17 @@ PromptDirectory::PromptDirectory(const std::filesystem::path& prompt_dir,
   std::filesystem::directory_iterator probe(prompt_dir_, ec);
   if (ec) {
     throw std::runtime_error(
-        "PromptDirectory: prompt directory is not readable: " +
+        std::format("PromptDirectory: prompt directory is not readable: {} ({})",
-        prompt_dir_.string() + " (" + ec.message() + ")");
+        prompt_dir_.string(), ec.message()));
   }
 
   if (logger_) {
-    logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+    logger_->Log(
-                 std::string("[PromptDirectory] Resolved prompt directory: ") +
+        {.level = LogLevel::Info,
-                     prompt_dir_.string());
+         .phase = PipelinePhase::Startup,
+         .message =
+             std::string("[PromptDirectory] Resolved prompt directory: ") +
+             prompt_dir_.string()});
   }
 }
 
@@ -65,13 +70,13 @@ std::string PromptDirectory::Load(std::string_view key) {
 
   // Scenario 3: resolve <prompt_dir>/<key>.md and require it to exist.
   const std::filesystem::path file_path =
-      prompt_dir_ / std::filesystem::path(key_str + ".md");
+      prompt_dir_ / std::filesystem::path(std::format("{}.md", key_str));
 
   std::ifstream file(file_path);
   if (!file.is_open()) {
     throw std::runtime_error(
-        "PromptDirectory: prompt file not found for key '" + key_str +
+        std::format("PromptDirectory: prompt file not found for key '{}': {}",
-        "': " + file_path.string());
+        key_str, file_path.string()));
   }
 
   std::string content((std::istreambuf_iterator<char>(file)),
@@ -79,15 +84,15 @@ std::string PromptDirectory::Load(std::string_view key) {
   file.close();
 
   if (content.empty()) {
-    throw std::runtime_error("PromptDirectory: prompt file for key '" +
+    throw std::runtime_error(std::format("PromptDirectory: prompt file for key '{}' is empty: {}",
-                             key_str + "' is empty: " + file_path.string());
+                             key_str, file_path.string()));
   }
 
   if (logger_) {
-    logger_->Log(LogLevel::Info, PipelinePhase::Startup,
+    logger_->Log({.level = LogLevel::Info,
-                 std::string("[PromptDirectory] Loaded prompt '") + key_str +
+                  .phase = PipelinePhase::Startup,
-                     "' from '" + file_path.string() + "' (" +
+                  .message = std::format("[PromptDirectory] Loaded prompt '{}' from '{}' ({} chars)",
-                     std::to_string(content.size()) + " chars)");
+                             key_str, file_path.string(), content.size())});
   }
 
   cache_.emplace(key_str, content);

tooling/pipeline/src/services/sqlite/helpers/sqlite_connection_helpers.cc

@@ -1,5 +1,6 @@
 #include "services/database/sqlite_connection_helpers.h"
 
+#include <format>
 #include <stdexcept>
 
 namespace sqlite_export_service_internal {
@@ -20,7 +21,7 @@ void SqliteStatementDeleter::operator()(
 void ThrowSqliteError(sqlite3* db_handle, std::string_view action) {
   const std::string message =
       db_handle != nullptr ? sqlite3_errmsg(db_handle) : "unknown SQLite error";
-  throw std::runtime_error(std::string(action) + ": " + message);
+  throw std::runtime_error(std::format("{}: {}", action, message));
 }
 
 SqliteDatabaseHandle OpenDatabase(const std::filesystem::path& path) {
@@ -50,7 +51,7 @@ void ExecSql(const SqliteDatabaseHandle& db_handle, std::string_view sql,
                                     ? error_message
                                     : sqlite3_errmsg(db_handle.get());
     sqlite3_free(error_message);
-    throw std::runtime_error(std::string(action) + ": " + message);
+    throw std::runtime_error(std::format("{}: {}", action, message));
   }
 }
 

tooling/pipeline/src/services/sqlite/initialize.cc

@@ -4,6 +4,7 @@
  */
 
 #include <filesystem>
+#include <format>
 #include <memory>
 #include <stdexcept>
 #include <string>
@@ -18,8 +19,8 @@ std::filesystem::path SqliteExportService::BuildDatabasePath() const {
 
   for (int suffix = 1; std::filesystem::exists(candidate); ++suffix) {
     candidate = output_path_ /
-                std::filesystem::path("biergarten_seed_" + run_timestamp_utc_ +
+                std::filesystem::path(std::format("biergarten_seed_{}-{}.sqlite",
-                                      "-" + std::to_string(suffix) + ".sqlite");
+                                      run_timestamp_utc_, suffix));
   }
 
   return candidate;

tooling/pipeline/src/web_client/http_web_client.cc

@@ -1,5 +1,5 @@
 /**
-* @file web_client/http_web_client.cc
+ * @file web_client/http_web_client.cc
  * @brief cpp-httplib implementation of WebClient.
  */
 
@@ -7,6 +7,8 @@
 
 #include <httplib.h>
 
+#include <chrono>
+#include <format>
 #include <regex>
 #include <stdexcept>
 #include <string>
@@ -31,7 +33,7 @@ std::pair<std::string, std::string> SplitUrl(const std::string& url) {
 
   return {match[1].str(), match[2].matched ? match[2].str() : "/"};
 }
-} // namespace
+}  // namespace
 
 std::string HttpWebClient::Get(const std::string& url) {
   const auto [origin, path] = SplitUrl(url);
@@ -40,28 +42,27 @@ std::string HttpWebClient::Get(const std::string& url) {
   client.set_follow_location(true);
   client.set_connection_timeout(kConnectionTimeoutSeconds);
   client.set_read_timeout(kReadTimeoutSeconds);
-  client.set_default_headers({
+  client.set_default_headers({{"Accept", "application/json"},
-     {"Accept", "application/json"},
+                              {"User-Agent", "biergarten-pipeline/1.0"}});
-     {"User-Agent", "biergarten-pipeline/1.0"}
- });
 
   const httplib::Result result = client.Get(path);
 
   if (!result) {
-    throw std::runtime_error(
+    throw std::runtime_error(std::format(
-        "[HttpWebClient] Request failed for URL: " + url +
+        "[HttpWebClient] Request failed for URL: {} — {}", url,
-        " — " + httplib::to_string(result.error()));
+        httplib::to_string(result.error())));
   }
 
   if (result->status < kSuccessMin || result->status >= kSuccessMax) {
     if (logger_) {
-      logger_->Log(LogLevel::Error, PipelinePhase::UserGeneration,
+      logger_->Log(
-                   std::string("[HttpWebClient] Request failed for URL: ") +
+          {.level = LogLevel::Error,
-                       url);
+           .phase = PipelinePhase::UserGeneration,
+         .message =
+           std::format("[HttpWebClient] Request failed for URL: {}", url)});
     }
-    throw std::runtime_error(
+    throw std::runtime_error(std::format("[HttpWebClient] HTTP {} for URL: {}",
-        "[HttpWebClient] HTTP " + std::to_string(result->status) +
+                       result->status, url));
-        " for URL: " + url);
   }
 
   return result->body;