If there is one place where most system design mistakes begin, it’s here: Designing without fully understanding the problem. It sounds obvious, but in practice, this is exactly what happens. We hear a problem statement and immediately start thinking about classes, APIs, or databases. The result? We end up solving the wrong problem very efficiently. Why requirements matter more than design Imagine building a food delivery system. If you assume: users can pre-schedule orders restaurants can reject orders delivery must happen within 30 minutes …but none of these were actual requirements, then your entire design is based on assumptions, not reality. And once design is wrong, everything built on top of it will also be wrong. The three layers of understanding Before you design anything, you need clarity across three dimensions. 1. Functional Requirements (What the system should do) These define the core behavior.…