A design review fails when the design comes before the problem, the alternatives are straw men, and open questions have no owner. This template puts the measured problem first, then goals and explicit non-goals, a layered architecture with a request flow, a scored comparison of options, an interface reference, a gated rollout with rollback, and a glossary that doubles as a list of open questions.

The sample is a design from Dovecote Systems to replace a 10-minute batch job with an event queue for order notifications: 1,200 requests a second, a 3x peak, a p95 target under 200 ms and a 6 engineer-week migration. Replace the problem, numbers, options and owners with your own, and delete sections you do not need.