An alert hits your radar, leaving you and your team perplexed. An “update” action that had worked for years suddenly ... didn't. You dig in to find that a subtle race condition had been hiding in plain sight all along. How could this happen? And why now? In this talk, we'll discover that seemingly improbable failures happen all the time, leading to data loss, dropped messages, and a lot of head-scratching. Plus, we'll see that anyone can become an expert in spotting these errors before they occur. Join us as we learn to write resilient save operations, without losing our minds.