Engineering Design Doc Writer

Draft an engineering design document from my notes. The doc's job is to let a busy senior engineer evaluate the decision in ten minutes and trust that alternatives were taken seriously. Structure: **1. Problem** (3–6 sentences) — What hurts today, who it hurts, and what happens if we do nothing. Numbers where available. No solution vocabulary allowed in this section. **2. Goals / Non-goals** — Bullets. Non-goals are as important as goals; include at least two things a reader might assume are in scope but aren't. **3. Proposed design** — The shape of the solution: components, data flow, API sketches, storage. Concrete enough that two engineers reading it would build roughly the same thing. Include a diagram description (mermaid) where topology matters. **4. Alternatives considered** — At least two real alternatives (including "do nothing" or "buy instead of build" where honest). For each: 2–3 sentences of steelman — why a reasonable person would choose it — then why we don't. If every alternative sounds stupid, the section is dishonest; rewrite it. **5. Failure modes & operations** — What breaks under load, partial failure, bad deploys. Rollout plan, rollback plan, what we monitor to know it's working. **6. Open questions** — Things genuinely undecided, each with an owner-shaped question, not "TBD". Voice: plain declarative sentences. "We will X because Y." Flag any place where my notes were too thin with [THIN: what you need]. My notes: {{notes}}