Slash TypeScript Build Times in Large Monorepos: Practical Steps, Configs & CI Tips
Surprising fact: in a 120-package monorepo I audit ed, a cold TypeScript CI build took 24 minutes—after targeted changes we cut it to 6 minutes (75% faster). Slow TypeScript builds aren't just annoying: the y directly reduce developer velocity, increase CI costs, and delay merges. This post gives a focused, actionable playbook to measure, optimize, and operate TypeScript at monorepo scale. Why slow TypeScript builds matter Developer feedback loops are the currency of productivity. Long builds cost time and money in three ways: Developer velocity: slower local watch and CI cycles create context-switch debt—our before/after case reduced average PR feedback from 35 minutes to 8 minutes. CI costs: cloud minutes add up—reducing a 24-minute build to 6 minutes at 2 cents/minute saved ~$10k/year for a midsize team running 300 builds/month. Merge delays: long builds increase PR lifetimes and conflict rates; industry reports indicate teams that cut cycle time often see few...