A practical guide to chaos engineering principles that transform fragile architectures into resilient, self-healing systems. Recently, I wrote an article titled “What if you are to build for one million daily active users?” . In that article, we explored a point where a monolithic system could no longer scale and began to break. We discussed scalability, availability, and observability, and why they become critical as systems grow. This article builds directly on that discussion. Here, the focus is designing for failure, what exactly is Chaos Engineering, how can we simulate chaos on our system, measure the impacts, and how to handle and mitigate failures on our system. The reality is that 100% uptime is not something you can realistically promise. What you can design for is fault tolerance and resilient infrastructure. That difference matters. A simple way to understand this is the idea of a spare tire in your car . You do not expect to have a flat tire every day, but you still keep a spare.…