During May 2025, Konstantin Tshnik focused on backend development for the peer-network/peer_backend repository, addressing API reliability and correctness. He resolved two targeted bugs using PHP, improving error reporting and response codes for post-related actions and chat retrieval endpoints. His work ensured that the API returned accurate status updates, such as handling empty or non-existent chats with a specific success code, thereby reducing ambiguous error states for clients. By refining response handling and aligning with business requirements for predictable behavior, Konstantin enhanced client stability and observability. The depth of his contributions reflects a careful, detail-oriented approach to backend engineering challenges.