Post mortem

Skill sinhoneyy/master-skills/plugins/master-skills-backend-engineer/skills/post-mortem

Unified skill library for Claude, Codex, Cursor, Antigravity & AI agents — 2,658 skills across 15 domains

Install

npx -y skills add sinhoneyy/master-skills --skill post-mortem

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What its author says it does

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/cs:post-mortem <decision> — Honest retrospective on an executed decision, scored against original assumptions and dissent. Closes the strategic sprint loop. Use when a decision hits its 90-day review checkpoint or its kill criteria trigger — e.g. scoring last quarter's pricing change against its pre-committed success metrics.

SKILL.md

3.8 KB, as published. Nobody here has run it

/cs:post-mortem — Honest Retrospective

Command: /cs:post-mortem <decision-path>

Closes the strategic sprint loop. Scores a decision against the success and kill criteria written before the decision (not retro-fitted) and revisits the preserved dissent. This is the rigor that compounds over time.

Pipeline Position

/cs:office-hours  →  /cs:brief  →  /cs:boardroom  →  /cs:decide  →  /cs:execute  →  /cs:post-mortem
                                                                                       ↑ you are here

When to Run

At the 90-day checkpoint (auto-scheduled by /cs:decide)
When a kill criterion triggers
After a major decision is reversed
Quarterly on all decisions of the past quarter

Inputs

The decision record (output of /cs:decide)
The execution plan (output of /cs:execute)
Actual outcomes (metrics, events, customer signals)

Output: Post-Mortem Record

Saved to ~/.claude/postmortems/YYYY-MM-DD-<slug>.md:

# Post-Mortem: <decision title>
**Decision date:** YYYY-MM-DD
**Post-mortem date:** YYYY-MM-DD
**Status:** WIN / PARTIAL / LOSS / MIXED

## Outcome Scoring (against pre-committed criteria)

| Success Criterion | Threshold | Actual | Met? |
|---|---|---|---|
| <metric 1> | <threshold> | <actual> | ✅ / ❌ |
| <metric 2> | <threshold> | <actual> | ✅ / ❌ |

| Kill Criterion | Threshold | Actual | Triggered? |
|---|---|---|---|
| <metric> | <threshold> | <actual> | ✅ / ❌ |

**Overall:** WIN / PARTIAL / LOSS / MIXED

## What We Got Right
- <factor 1>
- <factor 2>

## What We Got Wrong
- <factor 1>
- <factor 2>

## Preserved Dissent — Revisited
[Original dissent from the boardroom memo, scored:]

- **<dissenter>:** <original concern>
  - **Did it materialize?** YES / NO / PARTIAL
  - **Cost if YES:** <quantified impact>
  - **Lesson:** <one sentence>

## Assumption Audit
[Original brief's assumptions, scored:]

- **Assumption 1:** <text>
  - **Held?** YES / NO / PARTIAL
  - **Why:** <explanation>

## Process Lessons
- **Phase 2 isolation worked?** YES / NO
- **Devil's advocate concerns played out?** YES / NO / PARTIAL
- **Cadence was right?** YES / TOO LOOSE / TOO TIGHT

## Forward Actions
- [ ] <change to operating system or routing logic>
- [ ] <new decision to make based on this learning>
- [ ] <update company-context.md>

## Status
- WIN → archive, log lesson
- LOSS → schedule follow-up boardroom: `/cs:brief` for the next call

Why Pre-Committed Criteria Matter

The biggest temptation in post-mortems is retroactive justification: "we always knew X, that's why we did Y." Pre-committed criteria, signed at /cs:decide time, eliminate that move. The numbers either matched or they didn't.

Why Revisit Dissent

The dissent column from /cs:boardroom is the single most useful piece of organizational memory. Most of the time, the dissenter was directionally right. Revisiting and scoring it builds calibration over years.

Routing

/cs:brief — if the post-mortem surfaces a new decision
/cs:freeze — if the post-mortem reveals a process gap that needs cooldown enforcement
Updates to company-context.md via cs-onboard

Skill: decision-logger
Agent: cs-chief-of-staff
Sibling: /em:postmortem — adversarial single-decision post-mortem

Version: 1.0.0