Part 1: Serverless Is Not a Silver Bullet. What Lambdas Are Actually For

There's a particular kind of technical mistake that's easy to make and expensive to fix. It doesn't come from ignorance, exactly. It comes from taking something that works well in one context and applying it everywhere because it's available, familiar, and fits the current architecture on paper. Lambdas are a good example of this. I've seen this mistake made in production, at cost, by people who should have known better. But before I get into that, let's establish the foundation. What is AWS Lambda? Lambda is Amazon's serverless compute offering. The concept is elegant: you write a function, you define it's triggers, and AWS handles everything else. No server provisioning, no infrastructure management and no paying for idle time. The function runs, does what it has to and then disappears. That last part is vital: it disappears . Lambdas are ephemeral by design. They spin up to handle a task and shut down when they are done. This isn't a limitation, it's the point. It's what makes them