Paragrf worked on backend resilience and authentication reliability across apache/kvrocks and apache/brpc. In kvrocks, Paragrf developed failover features enabling CLIENT PAUSE/UNPAUSE commands, allowing client requests to be gracefully suspended and resumed during node failures, and implemented automatic topology updates to keep client routing accurate. This involved deep integration with the Redis protocol and robust C++ and Go unit testing to validate fail-state propagation. In brpc, Paragrf addressed gRPC authentication error reporting, standardizing error codes and messages for better client compatibility and observability. The work demonstrated strong backend engineering skills, with careful attention to protocol correctness and test coverage.