Lev focused on stabilizing the MQTT test suite for the photoprism/nats-server repository, addressing persistent race conditions and unreliable test outcomes. By implementing a per-test server lifecycle in Go, Lev ensured each MQTT test iteration started with a fresh server instance, which improved test isolation and reduced false positives in continuous integration. Additionally, Lev skipped unstable cluster connect and disconnect tests to further minimize CI noise. This backend development and testing work enhanced the determinism and reliability of the MQTT suite, enabling faster feedback cycles and clearer bug identification for future changes, reflecting a thoughtful approach to test infrastructure quality.