During January 2026, Dmytro Kulazhenko focused on backend stability for the ava-labs/avalanchego repository, addressing a critical crash in the TraceCall API. He implemented a guard against nil block numbers in BlockOverrides, preventing TraceCall failures that previously affected users relying on eth/tracers. Using Go, he supplemented this fix with targeted test coverage, ensuring the edge case was reliably handled and verified through continuous integration. Dmytro’s work demonstrated careful attention to production risk and robust testing practices, contributing to the reliability of avalanchego’s backend. His efforts reflected solid skills in API development, backend engineering, and automated testing within Go environments.