REST vs GraphQL vs WebSockets vs Webhooks: A Real-World Decision Guide (With Code)

You have used all of these. But when someone asks you, maybe in an interview, or in a system design meeting, why you chose WebSockets over polling, or webhooks over a queue, can you answer precisely? This isn't another definitions post. This article is about knowing which tool to reach for and why, with code you can actually use. Quick mental model before we start: Communication patterns → REST | GraphQL | WebSockets | Webhooks Code execution model → async/await These live at different layers. Conflating them is the most common source of confusion. async/await: The Foundation, Not the Feature Let's kill one myth immediately: async/await is not a communication pattern. It's how your server handles waiting. Every I/O operation — database queries, HTTP calls, file reads — makes your code wait. async/await ensures that waiting doesn't freeze every other user's request. # BAD: blocks the event loop - all other requests stall for 40ms @app.get("/order/{id}") def get_order(id: int): order = d