# Production Checklist

* [ ] **Run your own indexer** (don’t rely on public API for production).
* [ ] **Freshness**: refetch order **right before** filling; check `orderExpiryTimestamp`.
* [ ] **Slippage/Drift**: re-price UX; handle maker order exhaustion.
* [ ] **Decimals**: USDC 6dp; strikes/prices 8dp; rounding **down** contracts.
* [ ] **Referrer**: unique address; pass to every `fillOrder()`; portfolio filtering uses `referrer`.
* [ ] **Retries & Backoff** on `/update` and portfolio fetches.
* [ ] **Event Subscriptions**: watch `OrderFilled`, option deployments, and settlement events.
* [ ] **Error UX**: authorization, allowance, balance, expiry, signature mismatch.
* [ ] **Security**: validate inputs; never trust client-only calc for funds-moving ops.
* [ ] **Monitoring**: on-chain lag, API health, quote freshness, failure alerts.
* [ ] **Versioning**: pin ABIs & contract addresses; document migrations.