Author here! I think the comparison between Convex and Supabase is quite similar to Convex vs. Firebase! Supabase also encourages developers to load individual SQL queries from the client, supports edge functions without having a reactivity story for them, etc. Superbase is designed to be a Firebase alternative and appears to be taking most of their high-level approach.

you can put that on the server with postgres views in supabase

And RPC functions: https://supabase.com/docs/reference/javascript/rpc

+1. Also interested in this comparison!