Month: 2026-05 Focus: Deliver robust infix filtering with performance-oriented refactor, plus comprehensive test coverage for correctness and error handling. Key achievements (top 4): - Implemented Infix Filtering Support: added single-token infix search within fields marked as infix, with robust error handling for multi-token infix inputs and a refactored search path to support lazy evaluation. - Performance-oriented refactor: introduced lazy evaluation for infix search via search_infix_leaves(), reducing unnecessary work and improving response times for qualifying queries. - Core codebase refactor: updated include/index.h, src/index.cpp, and src/filter_result_iterator.cpp to integrate the new infix path, maintaining compatibility and improving maintainability. - Comprehensive test coverage: expanded test suite (test/filter_test.cpp) to validate InfixLazyEvaluation scenarios, exact-match behavior, and enable_lazy_filter flags, including regression tests for 400 error on multi-token infix. Overall impact and business value: - Enables substring-based search for infix fields, enhancing search relevance and user experience while keeping input validation strict to avoid ambiguity. - Improves performance for infix queries through lazy evaluation and streamlined data paths, reducing latency on common search patterns. - Strengthens code quality and reliability with thorough tests and clear failure modes (400 for invalid multi-token infix). Technologies/skills demonstrated: - C++ refactoring, search pipeline architecture, and lazy evaluation patterns. - Test-driven development with extensive unit and integration tests. - Debugging and validation of complex query paths and error handling. - Branch-level impact assessment via targeted test coverage and code changes.