Core idea

  • Shipping a front end, backend, and database is only the beginning. System design starts when popularity exposes limits in servers, databases, and response times. 0:00 0:24
  • The course starts with one server and one database, then introduces one fix per observed failure. This explains both why each component exists and what it costs. 0:59

Study lens

For every design change, ask:

  1. What failed?
  2. What is the smallest fix?
  3. What new cost or failure mode did the fix introduce?