Would be interesting to see a benchmark with the rust binary with successively more “bloat” in the binary to separate out how much of the cold start is app start time vs app transfer time. It would also be useful to have the c++ lambda runtime there too; I expect it probably performs similarly to rust.

Tangent: when you have a lambda returning binary data, it’s pretty painful to have to encode it as base64 just so it can be serialized to json for the runtime. To add insult to injury, the base64 encoding is much more likely put you over the response size limits (6MB normally, 1MB via ALB). The c++ lambda runtime (and maybe rust?) lets you return non-JSON and do whatever you want, as it’s just POSTing to an endpoint within the lambda. So you can return a binary payload and just have your client handle the blob.