Backend Fundamentals
What a backend actually is once the framework is removed: the request lifecycle end to end, which responsibilities belong to the server because they cannot be trusted to the client, and why every input from outside the process is untrusted.
A long-lived process holding the things a client cannot be trusted with, reached over a protocol it does not control.
Every hop between a client and a response, and the fact that each one can fail independently.
The list of duties that cannot be delegated to a client, a framework or a managed service.
Eleven questions to ask of any feature, in an order that surfaces the expensive decisions early.
Everything crossing into your process is untrusted — including responses from services you own.
Which question belongs to which domain, so you look for answers in the right place.
Keeping request-serving instances free of durable state, and being precise about which state that means.