It’s fine to use an AST interpreter if you pair it with really great JITs. That has its own problems though - using an AST as a shared source of truth for your

It’s fine to use an AST interpreter if you pair it with really great JITs. That has its own problems though - using an AST as a shared source of truth for your JIT compilers is cumbersome for implementing stuff like OSR. But from a perf standpoint, it’s probably fine. Also - say you want to optimize just for startup time, like if the code you’re running has minimal looping or reexecution. Then AST is better because you skip a step before first execution.