Cloudflare adds on-demand CPU and memory profiling for production Workers

Cloudflare introduced on-demand CPU and memory profiling for Workers and Durable Objects, generating interactive flamegraphs via the Observability dashboard or cf CLI. Profiles target an already-running isolate under real production traffic rather than a fresh one.

• V8 CPU profiler samples at 1 ms intervals without pausing request processing
• Profiles can be downloaded and analyzed with pprof
• Internal fix of a recursive JSON replacer made a Worker 2.7x faster
• Removing leftover Prometheus instrumentation cut p99.9 memory from 133 MB to 118 MB