Profile Guided Optimization for Go

Cloudflare is implementing Profile Guided Optimization (PGO) for its Go-based services to reduce CPU usage and improve resource efficiency. This involves collecting production CPU profiles, merging them, and recompiling services with the `-pgo` flag. Initial results show significant CPU savings, freeing up resources for customer requests. Future work includes automating profile collection, refining deployment processes, and exploring Link Time Optimization (LTO) techniques.