FastAPI vs Flask vs Django: which one for an AI backend in 2026

Picking the wrong web framework for your AI backend costs weeks of refactoring — usually when you're already under deadline pressure. In 2026, AI backends have specific requirements: streaming responses, async inference calls, structured input validation, and long-running requests. Here's how FastAPI, Flask, and Django actually hold up. What an AI backend actually needs Before comparing frameworks, be precise about the requirements: Streaming: LLM responses arrive token-by-token....