I Failed a Google System-Design Round. Here's the Architect's Loop I Built From It.

Fifteen famous interview articles won't make you an architect — reading fifteen blueprints is like reading fifteen recipes and calling yourself a chef. One repeatable habit will: name the trade-off (CAP, out loud) before you draw the box. The architect's loop — Constrain, Estimate, Sketch, Stress, Evolve — a method you can run under pressure, plus the fifteen topics re-grouped by the decision each settles (data plane, front door, async backbone, and the two case studies where a uniform strategy breaks on the tail). Written after a Google FDE round I didn't pass, learn-by-teaching.