Joeluu enhanced the Opetushallitus/ataru repository by developing an OID-based application search feature, enabling retrieval of applications by either a single OID or a list of OIDs. This work involved designing new SQL queries and extending service functions, streamlining data access and reducing query complexity for backend consumers. Leveraging skills in API development, backend development, and database management, Joeluu optimized the repository-service layer and maintained clear traceability through well-scoped git commits. The solution, implemented in Clojure and SQL, improved the efficiency and scalability of the search backend, laying a foundation for future OID-centric workflows within the system.