The problem: your build is slow and getting slower We've all been there. Your project starts small, builds take 2 seconds, and life is good. Six months later you've got 50 packages in a monorepo, a CI pipeline that takes 12 minutes, and developers staring at their terminals while the bundler chugs through node_modules for the hundredth time today. Then someone on Hacker News mentions that some tool got rewritten in Rust and suddenly the team is in a Slack thread debating whether to migrate the entire build pipeline to a different runtime. I get it. I really do. I spent two weeks last quarter trying to migrate a build pipeline before realizing the actual bottleneck was a 200-line postcss plugin that someone wrote in 2019 and never touched again. This post is about how to figure out where the slowness actually lives, before you commit to rewriting half your toolchain.…