Field notes
Architecture from inside the control loop.
Market, Routing, Bidding, Execution, Checkpointing: five systems borrowed from places that already solved them hard, joined so a workload can finish. One post per phase. No launch posts, no thought leadership.
Published
06-
Five systems, one control loop.
Nodus is not five products bolted together. It is a capacity book, a pure router, a reservation ledger, a generation reconciler, and portable progress, wired so reclaim re-enters the same path.
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The capacity book is not a catalog.
How we normalize supplier inventory into TTL’d offer snapshots, score health independently of price, and keep the router off every provider critical path.
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The router is pure on purpose.
Execution envelopes, cost-to-completion scoring, fallback graphs, and why a B200 the work does not need is a routing failure even when it is available.
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A bid ceiling is a completion budget.
Quote → bid → lease as financial truth. Recovery reserve, idempotent reservation attempts, and why we refuse to treat bidding as a speculative trading product.
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Launch is a midpoint.
Desired vs observed generations, runner identity before
running, and the reconciler that makes controller restarts and duplicate messages safe. -
Local disk is not progress.
PrepareCheckpoint, SHA-256 verified commits, immutable manifests, and Postgres compare-and-set for the latest pointer, so reclaim cannot erase the run.
Coming up
02-
Next
Fencing and the reclaim saga.
Signed reclaim → fence gen N → restore from latest manifest → re-route → reserve → gen N+1. Compensating actions at every step, and what the postmortem record must contain.
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Outline
Multi-stage DAGs without shared process state.
Manifest-only handoffs, per-stage continuity modes, and why a completed upstream stage never re-runs after a downstream reclaim.
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