Small PRs, big speedups: The Ruby performance work you almost missed - Closer to Code

The Ruby performance PRs worth knowing about - fast paths, fewer allocations, and benchmark-backed speedups across strings, files, GC, and the JIT.Normally I just fire off a tweet when I spot a nice performance PR landing in Ruby. Lately I've been catching up on a backlog of Ruby performance work I'd bookmarked and never gotten around to - so some of what's below isn't brand new, with a few PRs dating back to 2025. There were so many of them - some headline-grabbing, some small but delightfully clever - that a thread won't cut it. So here's a roundup instead, both the recent landings and the ones I'm late to. A few ground rules: every PR below ships a concrete benchmark number, so when I say "Nx faster" it's the author's own measurement, not vibes. Numbers come from different machines and workloads, so treat them as "here's the win on the benchmark that motivated the change," not cross-comparable lab results. Click through to any PR for the full picture - most authors document their methodology beautifully.