📢 THREAD: How We Cut Our CI Build Times by 70% ⚡️🛠 1/ Our CI pipeline hit 45 minutes per run. Devs stopped waiting for green checks and started merging on faith. Here's exactly how we got it to 13 minutes 🧵👇 #DevOps #CI #EngineeringCulture 2/ 🗄 Cache what doesn't change Dependency installation was eating 40% of every single run We fingerprinted the lockfile and restored a cached node_modules on match 18 minutes saved, no code changes required #CI #BuildPerformance 3/ ⚡️ Shard the test suite 4,000 tests were running sequentially on one machine We split them across 6 parallel runners, balanced by historical runtime Test stage: 22 minutes → 5 minutes #Testing #DevOps 4/ 💸 Pay for bigger runners Doubling CPU on the build stage costs $180/month That buys back 6 minutes per run At 60 runs a day, the math isn't close #EngineeringLeadership #DevProductivity 5/ 📈 The result 45 minutes → 13 minutes end to end Merge frequency doubled in the first month Rollbacks dropped — people started reading failing checks again #ShipFaster #DevEx 6/ 💡 TL;DR Cache dependencies on a lockfile fingerprint Shard tests across parallel runners by runtime Buy faster hardware; engineer hours cost more than CPU #DevOps #CI 7/ 🌍 Your pipeline can be fast too Slow CI isn't a fact of life — it's a backlog of small decisions. Follow us for more engineering deep dives. @mention the teammate who's been waiting on a build all morning 👀 🔗 Full write-up: [link] #DevOps