Benchmark results aside, JVM has very little to do with the startup time. Most of the time is spent wiring Clojure namespaces together: every namespace must be

Benchmark results aside, JVM has very little to do with the startup time. Most of the time is spent wiring Clojure namespaces together: every namespace must be evaluated, every Var initialized. That takes time. The core reason for that is that namespaces and vars are dynamic, not immutable, and Clojure runtime has to evaluate everything on each startup to uphold language semantics.