The Hidden Trap in Backend Tutorials: Why Your Webhooks Are Creating Duplicate Data (And How to Fix It) (opens in new tab)

We've all been there. You're sitting at your desk late at night, watching a backend tutorial, fueled by coffee and determination. The instructor shows you how to integrate a payment gateway or a webhook, and it looks incredibly simple: Receive the webhook event. Update the database. Return a 200 OK. You write the code, test it locally, and it works perfectly. You push it to production feeling like a senior engineer. But a few days later, you check your database and notice something terrifying...