I'm not part of the Deno team, but can give my view on a few things. FFI Deno's FFI has recently been changing quite a bit, and moving to a more direct binding. The numbers used on Bun's website (around 350 ns per FFI call) seem in line with what the FFI performance was after my semi-recent addition of FFI callbacks, during which I also ended up adding a lot of JS-side overhead. A later PR by the