System 03 / Reconciliation / systems dossier
Every number deserves a history.
A history-first model for stock, balances, returns, and split payments. Every number keeps a traceable reason.
Working principle
The total is an answer. The history makes that answer believable.
The consequence path.
A system is a sequence of promises. Each boundary needs proof before state advances.
- 01 — Command
- 02 — Invariant check
- 03 — Projection
- 04 — Audit trail
Decision record.
Choose an explainable history over mutable convenience. Summaries can be rebuilt; the events that justify them must stay intact. Audit trails are product requirements, not afterthoughts for compliance season.
Not every technically possible action belongs in the product. The useful decision is the one that keeps business state explainable after the screen, dependency, or operator has moved on. Timeouts stay unknown until verified. Redirects stay navigational until reconciled. Totals stay provisional until their history can answer why.
What the system had to carry.
- Stock moves through stock events.
- Balances move through ledger entries.
- Split payments reconcile exactly.
- Returns create compensating events.
- Adjustments retain actor, reason, time, and reference.
Resulting operating model.
A system model built for reconciliation, audit review, and recoverable business operations when the displayed total and the human story temporarily disagree.
Public evidence stays qualitative and privacy-safe. Deeper architecture, implementation detail, and production references are available in a relevant conversation.