When Your Single Point of Failure Fix Breaks: Why Repair-First Programs Need a Chain Check
You've been up since 3 AM. The database replica failed, and your primary is overloaded. You add a second read replica, push to production, and go back to sleep. Next week, the same thing happens—but now the load balancer is the bottleneck because it can't handle the three replicas you added. Fixing a single point of failure (SPOF) is rarely a one-and-done job. Without checking the chain, you're just moving the weak link. This isn't theory. I've seen teams swap out a broken caching layer only to discover the new one has a hard memory limit that kicks in under peak traffic. The fix worked for 48 hours. Then the new SPOF appeared. In repair-first programming, we treat incidents as opportunities, but only if we look at the whole dependency graph. Here's how to choose a SPOF fix that lasts—and how to avoid the trap of the quick patch.