I kind of forgot that while lambda only supports node, you can use it as a glorified wrapper to call your c++ code
I'm the creator of the project. We currently support 11+ programming languages.
Here's a template if it helps anyone:
We're adding support for more languages (JS & Python currently) but also have an entire build chain that let's you specify any Linux OS and language packages you want, and it's also trivial to embed your binaries and shell out to them if needed.
To improve performance, AWS Lambda may choose to retain an instance of your function and reuse it to serve a subsequent request, rather than creating a new copy. Your code should not assume that this will always happen.