Session Retrospective

Reviews what happened during the session, extracts durable learnings, and keeps LEARNINGS.md lean.

Steps

1. Scan the session. Identify moments where:
   • An approach was tried and failed.
   • An approach was tried and worked against expectation.
   • A tool / API / environment quirk was discovered.
   • A user correction changed direction.
   • A hypothesis was confirmed or rejected by data.
2. Filter to durable material. Drop anything already recorded in code, git history, a commit message, or an existing learning. Target: 0 to 3 new learnings per session; zero is a valid answer.
3. For each surviving item, invoke the capture-learning skill (one per item).
4. Update LEARNINGS.md digest:
   • Pull the 10 most recent scar + pattern learnings across all competitions.
   • Render them as - L-… — <Rule> (scope, cost) under the <!-- BEGIN:RECENT --> block.
   • For any learning with recurring: true OR cost: high, also ensure it appears in the <!-- BEGIN:PINNED --> block (dedupe by ID).
   • Keep pinned ≤ 15 entries. Evict the oldest non-recurring high-cost ones when over budget.
   • Alternatively, run scripts/kln digest to rebuild both blocks automatically.
5. Detect recurrence. For any newly-captured scar, run grep -l -i "<same root cause>" .learnings/L-*.md. If the same root cause has appeared ≥ 2 times, mark recurring: true in the new file AND the older file(s), and add to pinned.
6. Prune stale. If any learning references code paths that no longer exist, a Kaggle API behavior that has changed, or a library version no longer in use, move it to .learnings/archive/ with a one-line reason in its frontmatter (archived_reason: ..., archived_date: ...). Never silently delete.
7. Write a 3-line summary to the user:

   Retro:
     Captured: L-…, L-…
     Pinned: L-… now recurring
     Archived: L-… (API deprecated)

When there's nothing to capture

Say so in one line: "Retro: no durable learnings this session." Do not invent. Do not pad. Zero learnings is compatible with a productive session.

Creative directive — the scar compiler

Think of yourself as editing a project post-mortem wiki. Every line should be readable by a stranger. Rules first, war stories second. If a learning file reads like a diary entry, rewrite the Rule line so the future reader doesn't have to unpack the story.