Ask HN: Light weight architectures for ChatGPT-based web app

As AI applications are suddenly booming due to the recent development of AI model such as ChatGPT. I'm wondering what are the best/typical light weight architectures and tech stacks for ChatGPT-based web apps such as https://chat.openai.com/ so that we can rapidly test a lot of ideas.

I knew/researched some options below but not sure what's the typical combination of them or some further details.

- Frontend: React/Vue/Angular. Easy to decide (hint: ask ChatGPT). But how about UI frameworks/libraries? where to host it? vercel?

- Backend: Node.js? is express.js still a good/typical choice? but how about Serverless? Do we need Socket.io alike frameworks to do chat(bot) based web apps? where to host the backend? vercel can do the job too or AWS or GAE?

- DB: traditional DB or Firebase alike?

How to create the web app project? I guess it's frontend or backend framework dependent.

Sorry for those beginner questions as my tech background is limited to my iOS + some Java + some RoR days.