Mikolaj Nowak focused on backend and API development across Kong’s open-source repositories, addressing configuration correctness and data integrity. He enhanced the Kong/kong Admin API by implementing validation logic in Lua to reject null or empty tag arrays, improving contract enforcement and preventing inconsistent data. In Go-based projects like go-kong and go-database-reconciler, he introduced diffing algorithms and configuration management features, such as ClearUnmatchingDeprecations, to synchronize plugin configurations and handle deprecated fields accurately. Mikolaj also updated integration tests in deck using Go and YAML, ensuring test reliability and deployment stability. His work demonstrated depth in backend systems and robust test coverage.