Model tenant boundaries explicitly
A multi-organization application does not automatically provide tenant isolation. Sensitive queries and mutations should operate under validated server-side tenant context, and endpoints need corresponding authorization rules.
Database constraints, transaction boundaries and audit trails create additional protection against implementation errors.
Authorization is a server-side contract
The UI may hide unavailable actions for usability, but it cannot be the final authority. APIs should enforce permissions and return predictable error contracts.
Cross-tenant access and privilege-escalation tests belong in mandatory regression coverage.
Migrations should not trade data safety for speed
Use expand-and-contract schema evolution: introduce compatible changes, migrate and verify data, switch read/write paths, then retire old structures safely.
Retried writes and concurrent operations need idempotency keys, appropriate transaction boundaries or concurrency controls.
Meaningful observability
- Contextual metrics without exposing sensitive tenant data.
- Request IDs and structured logs for tracing cross-module failures.
- Explicit ownership for incidents, backups and rollback.