The author wrote a tiny AST and bytecode interpreter to test which is faster (related to the paper "AST vs. Bytecode: Interpreters in the Age of Meta-Compilation").

Tl;dr; like in the paper, the AST interpreter is faster.

Keep in mind the "meta-compilation": the AST or bytecode interpreter itself runs in a JIT interpreter, in the author's tests V8 or JSC.

Github