Roll out Content Security Policy through resource inventory, report-only observation, nonce or hash migration, staged enforcement, and tested rollback.
Model instants, local dates, recurring schedules, and durations separately, with explicit RFC 3339, IANA time-zone, DST, and clock contracts.
Ship passkeys with complete WebAuthn verification, Apple and Android domain association, multi-credential account management, and resilient recovery.
Build queryable, trace-correlated logs with stable event schemas, explicit severity, pre-export redaction, cardinality budgets, and failure tests.
Design retry classification, server-side idempotency records, conditional updates, bounded backoff, and failure tests for state-changing HTTP APIs.