During June 2025, Zemlya focused on improving authentication reliability in the Netflix/lemur repository by addressing a critical issue with JWT token formatting. They ensured that user IDs, stored as the subject claim in JWTs, were consistently handled as strings during token creation and correctly converted back to integers during validation, preventing authentication failures and 403 errors. Zemlya also updated test vectors to accurately reflect the new token formatting, supporting more reliable end-to-end testing. Their work demonstrated a solid understanding of backend development and authentication, utilizing Python and JWT standards to enhance both the robustness and testability of the authentication system.