Worked on the envoyproxy/envoy repository to optimize HTTP header parsing performance, specifically targeting the Balsa HTTP/1 token validation path. Developed a constexpr bit-mask technique in C++ to replace the previous per-character binary search, resulting in faster token validation and reduced CPU usage during hot-path parsing. The approach was validated through comprehensive benchmarking and unit testing using Bazel, with reproducible tests and detailed benchmark commands provided for future regression protection. This optimization improved HTTP header parse throughput and lowered per-request CPU costs, supporting higher QPS and better latency profiles for high-traffic deployments while demonstrating strong skills in C++ and performance engineering.