Worked on the citrineos/citrineos-core repository to address a critical backend issue affecting OCPP requestId handling. Focused on backend development using JavaScript, TypeScript, and Sequelize, the work involved converting Sequelize BIGINT values to JavaScript numbers to ensure data type integrity and OCPP protocol compliance. Introduced a dedicated helper function for number conversion and revised sequence value retrieval logic to prevent JSON exceptions in OCPP 2.0.1 charger payloads. Comprehensive unit tests were added to cover edge cases and reduce regression risk. The approach emphasized maintainability, aligning with repository standards and strengthening both data integrity and test coverage throughout the codebase.