Vercel and supabase seems to be the norm around here.

DX is simple, integrations between the two, and the stack is well understood by the LLM.

Lovable uses supabase, and is surprisingly easy to eject from too; I've done the lovable to Vercel + supabase a couple of times, even managing to keep it syncing via the Git integration. You can get proper scalable infra and minimal vendor lock in whilst the vibe coder gets to play with the pretty.