The unsafe default
Teams often stop at successful sign-in screens and miss deeper auth failures that cause real incidents.
Failure modes to watch
- Missing server-side authorization checks
- Long-lived sessions without revocation paths
- Weak account recovery controls
Safer implementation patterns
- Design permission checks per action, not per page.
- Expire and rotate sessions with device visibility.
- Instrument suspicious auth flows and alert on anomalies.
Minimum controls for small teams
- Threat model account takeover paths.
- Test horizontal/vertical privilege boundaries.
- Protect recovery workflows like production auth.
Builder note: Security posture is mostly defaults and review discipline, not heroics.