Why Retry Is One Of The Most Dangerous Keywords In Software

Few lines of code look more innocent than this: retry ( 3 ) It feels responsible. Professional. Resilient. After all, networks fail. Servers become unavailable. Databases occasionally time out. Retrying seems like the obvious solution. And sometimes it is. But after enough years building production systems, I've become convinced of something: Retry is one of the most dangerous keywords in software. Not because retries are bad. Because retries amplify everything. Good systems become more reliable. Bad systems become disasters. The problem is that many developers treat retries as a reliability feature when they're actually a distributed systems feature. And distributed systems are where simple ideas go to become complicated. Why Retries Exist Imagine: await fetch ( " /api/users " ); The request fails. Maybe: Network hiccup Temporary database issue Load balancer restart Service deployment The operation might succeed if attempted again. So we write: retry ( 3 ) Seems reasonable. And in many cases: It Works Which is why retries become popular. The Dangerous Assumption Most developers unconsciously assume: Failure = Operation Did Not Execute Unfortunately that's not always true. A request can: Execute Successfully ↓ Response Never Arrives From the client's perspective: Failure From the server's perspective: Success Now a retry becomes dangerous. The Double Payment Problem Imagine a payment service. await chargeCard ( order ); The card processor successfully charges: $100 The response is lost due to a network issue. Client sees: Request Failed and retries. await chargeCard ( order ); again. Now: Charge #1 = Success Charge #2 = Success The customer paid twice. Nobody wrote bad logic. The retry created the bug. The Email Storm Problem Consider: await sendWelcomeEmail ( user ); Email provider accepts the message. Response times out. Application retries. await sendWelcomeEmail ( user ); again. Customer receives: Welcome! Welcome! Welcome! Welcome! Support ticket created. Marke