Learning Platformindex / ADRs9 tracks · worked

The Engineering Meat

Architecture Decision Records

Every one of the nine tracks worked all the way down by the same adversarial 5-lens design panel — options, a divergent panel, a convergent decision, a tradeoff matrix, new invariants + required evals, and preserved dissent. The panel produced a coherent doctrine across all of them: own the source-of-truth and the permission authority · rent the commodity mechanics · defer the sophistication behind a measured trigger.

ADR-001 · E4 + E5 · Community & Messaging
Own the log · rent the rendering · defer the bells
The template. Append-only conversation log as source of truth; boards/DMs/feed are derived views; tier at read; outbox → the AI index; borrow rendering + realtime as dumb pipes; defer presence + the ranking agent. Drills into the 5-lens panel and the architecture diagram.
Open ADR-001 →
ADR-002 · E1 · Iron & topology
Own the stateful core · rent the spike · grow by repoint
One owned box for all durable state; rent the spiky stateless edge (GPU inference, live-event egress); the fault line is stateful-vs-spiky, not workload-vs-workload; instrument before you size.
Open →
ADR-003 · E3 · Identity, SSO & Security
Own the join key · rent the protocol · defer the daemon
Own the sub as the one join key; adopt a standard SSO protocol rather than hand-rolling; audit the existing auth first; don't stand up a heavy identity daemon before the tier actually needs it.
Open →
ADR-004 · E6 · AI & agentic layer
Own the emit-and-tier contract · rent the retrieval mechanics · re-earn the quality · defer the ranker
Own the write-into-index + tier-at-retrieval contract; borrow the retrieval/embedding mechanics; gate quality with evals; ship the simple feed first, defer the ranking agent.
Open →
ADR-005 · E7 · Video & content
Own the row · rent the spike · never build the transcoder
Own the media metadata row (the object model); rent the delivery spike (a paid host/CDN for live); never hand-build a transcoding pipeline — delivery is a URL repoint by design.
Open →
ADR-006 · E8 · Payments, tiers & entitlements
Own the entitlement · rent the rails · defer the machinery
Own the entitlement model (tier as the single source of truth, enforced at read); rent the payment rails (a processor); ship one paid tier before the full four-tier + vetting machinery.
Open →
ADR-007 · E9 · Governance, tracking & build
Own the tracking log · one gate for the moat · deterministic ≠ probabilistic · defer the ceremony
Own the three-way tracking record; one hard gate on the moat (the tier-leak eval); keep deterministic gates separate from probabilistic evals; defer process ceremony behind named triggers — don't over-govern a build with no code yet.
Open →
ADR-008 · E2 · Learning-core seams
One writer to identity · adopt don't reissue · emit don't share · import don't adapt
The learning core is settled — this is the seams: one writer to the identity store; adopt its auth under the IdP rather than reissuing; emit its course/cert events into the index rather than sharing its DB; import the question banks rather than adapting them.
Open →
What the panel proved. Nine independent adversarial panels, run blind of each other, converged on the same doctrine — own the durable record + the permission authority, rent the commodity, defer the sophistication behind a measured trigger. That coherence across tracks is the strongest signal the foundation is sound. Each ADR carries its own new invariants, required evals, and preserved dissent.

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