I don't really think we're competitors, their focus is on JS/TS eco system. As you suggested Stelvio focuses on Python and aims to really nail down experience for deploying Python to AWS (and later potentially elsewhere). e.g. we resolve python dependencies for lambda functions and layers and package them for you etc.
In the long run we want Stelvio to be a go to tool for deploying Python (with some nice TUI and web console to make it all really smooth).