It’s a clever technique no doubt. In practice for JS-centric workloads (which we’ve found is the bulk of demand), using V8 is still much much more efficient, has faster performance than Wizer’s approach and easier to scale out (the scale that Workers runs at can boggle the mind).

We are trying to figure out how to move more of the API parts of runtime to something not c++ without significantly negatively impacting memory / CPU (safety, correctness, speed of development, etc). It’s an interesting problem to try to do at Cloudflare scale.