During December 2025, Cardiff Giant focused on backend stability for the citrineos/citrineos-core repository, addressing a critical bug in OCPP requestId handling. Using JavaScript, TypeScript, and Sequelize, Cardiff refactored the data flow to ensure that long numeric values from the database were correctly converted to JavaScript numbers, preventing JSON exceptions in OCPP 2.0.1 charger payloads. The solution included introducing a dedicated helper for number conversion and updating sequence retrieval logic. Comprehensive unit tests were added to cover edge cases, improving reliability and maintainability. Cardiff’s work demonstrated careful attention to data integrity and robust backend engineering practices throughout the project.