System Design Interviews: The 10 Concepts Every Senior Engineer Must Master

System design interviews are the critical gating factor for senior engineering roles at major tech companies like Facebook, Google, and Amazon, where interview performance directly impacts salary negotiations and career trajectory—potentially worth tens of thousands of dollars annually. Unlike coding interviews, system design assesses your ability to architect scalable, extensible solutions and make informed trade-offs between competing technologies, a skill set that distinguishes senior engineers from their peers. Mastering fundamental concepts like load balancing, databases, caching, and CAP theorem is therefore essential for anyone pursuing advanced engineering positions.