June 23, 2026Practice
Arena 90 campaign contract and research audit
Arena 90 now publishes a clearer pinned-route contract: 90 stable problem IDs, prerequisites, medals, and coverage snapshots.
New
- Published a clearer Arena 90 contract with 90 stable problem IDs, prerequisites, medals, and coverage snapshots.
- Added a public research note that explains topic balance, test-count coverage, and the route contract.
Changed
- The campaign story now emphasizes pinned practice work instead of treating the map as decorative art.
- Medal and progress language is tied to auditable problem coverage.
Fixed
- Removed ambiguity around what a campaign node represents when the underlying problem bank changes.
Why it matters
- Learners, educators, and future product notes can point at the same stable campaign path instead of a drifting query result.