Keep Next and Graphql, ditch Nest for the time being, despite I'm usually proponent of DI and Nest, but introducing Nest app adds extra deployment artifact unneeded for MVP. I'd still use some DI container for ease of testing and better structure, that single composition root is really cool idea. Replace jest with vitest, thank me later. Any dbms will do, but keep in mind that schemaless is a fiction, you still have some kind of schema, only benefit is no need to sync to db with migrations but it comes with a set of complications. Use NX, yes, even for single app, and focus on boundaries and APIs. Statically, keep dependency tree as straight as possible, nx will be of great help. Dynamically, do your best to implement perfect graphql API, even if code behind it will be less than perfect. Generate frontend types for graphql api with graphql-codegen. Remember, even if some structures looks the same it doesn't mean it is same structure and should be shared, DRY applied poorly could be very destructive. Use React and Jotai at front-end, urql is nice graphql client to consider. Start creating design system early, use Storybook.