If I completely clear all cached packages maybe, but I never do that locally or in CI/CD, and that's true of Python too (but no doubting UV is faster than Maven). Clojure/JVM startup time is less than half a second, obviously that's still infinitely more than Python or a systems language but tolerable to me. First test runs after about 2s? And obviously day to day these things run instantly because they're already loaded in a REPL/IPython. Maybe unfair to compare an interpreted language to a compiled one: building an uberjar would add 10 seconds but I'd never do that during development, which is part of the selling point I guess. Either way, I don't think the JVM startup time is really a massive issue in 2025, and I feel like whatever ecosystem you're in, you can always attack these slow test suites and improve your quality of life.