There's no best way to architect anything. It's always a trade-off and depends tightly on your situation.

Here's some practical advice. I would just look at loads of starter projects by googling "express typescript starter github" then explore each project. Things to remember when searching:

- Most starter projects have too many use cases, so you can actually delete parts you don't need.

- You don't need to use a single architecture, it may be better to combine things you like about a few different types