My first choice if the product is a good fit would be old school Django deployed to a single VPS (no docker). I am creating a public starter kit that does exactly that, including the deployment part: https://stribny.github.io/sidewinder/

However, there are lots of use cases that would call for additional SPA (Vue/Nuxt), or other tech. So in that case I'd add it or replace the tech stack entirely. I'd probably avoid specialized cloud services, might consider something like https://supabase.com tho if the app doesn't need a complex backend.