Decision Log

Record decisions with context, options considered, and rationale. Retrieve and explain past decisions so teams and future-you know why something was chosen.

When to Use

• User wants to document a decision (ADR, decision record, "why we chose X")
• User asks "why did we choose X?" or "what was the decision on Y?"
• User wants to review options before deciding
• User is building or maintaining a decision log

Workflow

1. Context: What is the decision about? (scope, constraint, trigger)
2. Options: What were the options considered? (2–5)
3. Criteria: What matters? (cost, speed, risk, maintainability, etc.)
4. Decision: What was chosen?
5. Rationale: Why? What trade-offs?
6. Consequences: What follows? (follow-up work, reversibility, review date)

Decision Record Format

# [Decision Title]

**Date**: YYYY-MM-DD  
**Status**: Proposed | Accepted | Deprecated | Superseded by [link]  
**Deciders**: [who was involved]

## Context

[What situation or problem led to this decision? What constraints exist?]

## Options Considered

### Option A: [Name]

- **Pros**: [list]
- **Cons**: [list]

### Option B: [Name]

- **Pros**: [list]
- **Cons**: [list]

### Option C: [Name]

- ...

## Decision

**[Chosen option]** because [1–2 sentence rationale].

## Rationale

[Why this option? What trade-offs were accepted? What was rejected and why?]

## Consequences

- [What we gain]
- [What we give up or risk]
- [Follow-up work]
- [When to revisit: e.g. in 6 months, or when X happens]

## References

- [Link to ticket, doc, or discussion]

Keep each record to one decision. Use "Superseded by" when a later decision replaces this one.

When to Create a Record

• Technical: Architecture, stack, library, API design, data model
• Process: How we run meetings, deploy, review, onboard
• Product: Feature scope, prioritization, rollout strategy

Skip for tiny, reversible choices (e.g. variable name). Use for choices that affect others or are hard to undo.

Retrieving Decisions

When someone asks "why did we choose X?":

1. Search decision log (or codebase for ADR files)
2. Return the matching record: context, options, decision, rationale
3. If superseded, point to the newer decision and brief reason

If no record exists: say so and offer to draft one from what's known or from conversation.

Lightweight Variant

For quick logs without full ADR format:

## [Date] [Decision in one line]

- **Context**: [1 sentence]
- **Options**: A, B, C
- **Chosen**: A. **Why**: [1 sentence]
- **Follow-up**: [any]

Tone and Style

• Neutral and factual
• Past tense for what was decided
• Clear "we chose X because Y"
• No blame; focus on rationale and trade-offs

Anti-Patterns

• ❌ Recording every tiny choice; reserve for meaningful decisions
• ❌ Only stating the outcome without options or rationale
• ❌ No date or status (hard to know if it's still current)
• ❌ Mixing multiple decisions in one record