REST API Best Practices — ELI5

Imagine you run a restaurant. Customers sit down, read the menu, and place orders. The kitchen cooks the food and sends it back. A REST API works the same way — it’s the menu and ordering system for software.

Best practices are the rules that keep your restaurant running smoothly. Things like: put clear names on the menu (don’t call a burger “item 47”), always tell the customer if something is out of stock instead of silently giving them nothing, and don’t make them re-explain their entire order if they just want to add a drink.

In Python, when you build a REST API with tools like FastAPI or Flask, best practices mean:

• Use clear names. If someone asks for /users/5, give them user number 5. Don’t make them guess what URL to visit.
• Tell people what happened. If something went wrong, say so clearly (“we’re out of soup”) instead of just going silent.
• Don’t make them repeat themselves. If someone already logged in, remember that — don’t ask again on every request.
• Keep it predictable. A GET request always gets something. A DELETE request always removes something. No surprises.

Bad APIs are like a restaurant where the menu is in code, the waiter ignores you, and sometimes ordering a salad accidentally deletes your account. Nobody wants to eat there.

One thing to remember: A great API feels invisible — people use it without thinking because it just makes sense.