Technical design document draft

Draft a technical design document for the following.

Problem or feature: {{problem}}
Background and current system: {{background}}
Constraints (deadline, team, budget, tech, compliance): {{constraints}}
Options I am already considering: {{options}}
Audience: {{audience}}

Structure the document with:
1. Summary: three sentences, readable alone.
2. Context and problem: why this matters now and what happens if we do nothing.
3. Goals and non-goals: measurable goals; non-goals that prevent scope arguments.
4. Proposed design: components, data flow, key interfaces or data models, and a simple text diagram if useful.
5. Alternatives considered: at least two, including my options, each with an honest comparison and the reason it was not chosen.
6. Key tradeoffs and open questions: what we are giving up, and the questions reviewers must answer.
7. Rollout plan: phases, feature flags, migration, backward compatibility and how to roll back.
8. Testing and observability: how we will know it works in production, with specific metrics and alerts.
9. Risks and mitigations.
10. Effort estimate in rough ranges with the assumptions behind them.

Be specific and direct. Where my input lacks a fact you need, write the assumption in a bold "Assumption:" line rather than inventing details. Do not pad sections that do not apply.