Technical design document
Align on the problem and consequential decisions before expensive implementation.
# Context and problem
# Goals / non-goals
# Requirements and constraints
# Proposed design
# Alternatives considered
# Data and API changes
# Security and privacy
# Failure modes and observability
# Rollout / rollback
# Open questions- Keep the document proportional to the decision's cost and reversibility.
- Separate requirements from the proposed solution.
- Show alternatives and why they were rejected.
- Invite review from affected owners before implementation.
Key idea: The value is alignment and decision quality, not document length.