FastAPI vs Flask vs Django — When to Use Which

# --- FASTAPI: Type-Driven Architecture ---
from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()

class ForgeUser(BaseModel):
    name: str
    tier: str = "Standard"

@app.post('/forge/users')
async def create_fast(user: ForgeUser):
    # Automatic validation, coercion, and Swagger docs
    return user

# --- FLASK: Explicit & Manual ---
from flask import Flask, request, jsonify

app_flask = Flask(__name__)

@app_flask.route('/forge/users', methods=['POST'])
def create_flask():
    data = request.get_json()
    # Manual validation required here (or add Marshmallow)
    if not data or 'name' not in data:
        return jsonify({"error": "Missing name"}), 400
    return jsonify(data)

# --- DJANGO DRF: Enterprise Pattern ---
# In Django, you would define a Model, then a Serializer:
# class UserSerializer(serializers.ModelSerializer):
#     class Meta: model = User; fields = ['name', 'tier']
# This creates a massive amount of structure but more 'boilerplate'.