Related Systems
Reviews of external systems doing similar work — knowledge management for AI agents, context engineering, structured note-taking.
Why we track these
Convergence across independent projects is a stronger signal than any single design argument. When three unrelated systems arrive at filesystem-over-databases, that's evidence. When one system makes a bet we haven't considered, that's a prompt to think harder.
How to write a review
Use the template: kb/notes/types/related-system.md
The recurring structure: what it is → core ideas → how it compares → what to borrow → what to watch.
The "Borrowable Ideas" section is the most important deliverable. Each review should produce concrete candidates for adoption — not just "interesting" observations but things shaped enough to act on. For each borrowable idea, say what it would look like in our system and whether it's ready now or needs a use case first.
Staleness
Reviews have a last-checked field in frontmatter. A review is stale when:
- The reviewed system has had a major release or architectural change since
last-checked - Our own system has evolved enough that the comparison section no longer reflects reality
- More than 3 months have passed without re-checking
Stale reviews should be updated or demoted to status: outdated. Don't delete — the comparison history has value even when the details drift.
Spin-off notes
A review may produce spin-off notes (like thalo-type-comparison.md) when a specific comparison deserves deeper treatment. These live in this directory alongside the main review and link back to it.
Index
The related-systems-index.md is a curated index with a "Patterns Across Systems" section. Update it when adding a new review — the cross-system patterns are as valuable as individual reviews.