# Feature flags or toggles configured for high-risk deployments; toggleable without code redeployment

- **Pattern:** `ab-000979` (`deployment-readiness.monitoring-alerting.feature-flags`)
- **Severity:** medium
- **Lifecycle:** active
- **Last modified:** 2026-04-18
- **Canonical URL:** https://auditbuffet.com/patterns/ab-000979
- **License:** CC-BY-4.0 — attribute to AuditBuffet Pattern Catalog (https://auditbuffet.com/patterns/ab-000979)

## Why it matters

Deploying a high-risk feature without a feature flag means the only remediation for a bad release is a full rollback — redeploying old code, re-running migrations in reverse, and potentially incurring downtime. NIST CM-3 covers controlled configuration changes; feature flags implement that control at runtime without touching infrastructure. A flag that can be toggled in a dashboard in seconds is vastly safer than a rollback that takes 15 minutes. Teams without feature flags tie their deployment risk directly to their rollback speed.

## Severity rationale

Medium because missing feature flags force full rollbacks for high-risk feature failures, but the risk is only realized when a high-risk feature ships and misbehaves.

## Remediation

Integrate a feature flag service such as LaunchDarkly (free tier) or self-hosted Unleash for high-risk or experimental features.

```bash
npm install @launchdarkly/react-client-sdk
```

Wrap high-risk features in a flag check:

```tsx
import { useFlag } from '@launchdarkly/react-client-sdk';

export function CheckoutFlow() {
  const newCheckout = useFlag('new-checkout-flow', false);
  return newCheckout ? <NewCheckout /> : <LegacyCheckout />;
}
```

Configure the flag default to `false` (off) and enable it incrementally: 1% → 10% → 50% → 100% of traffic. If error rates spike at any stage, toggle the flag off in the LaunchDarkly dashboard — no code change, no deployment, no downtime.

## Detection

- **ID:** `feature-flags`
- **Severity:** `medium`
- **What to look for:** Enumerate every relevant item. Look for feature flag library in dependencies: `launchdarkly`, `unleash`, `split.io`, or custom implementation. Check for feature flag usage in code (conditional logic based on flags). Verify flags can be toggled in a dashboard or configuration service without redeployment.
- **Pass criteria:** At least 1 of the following conditions is met. Feature flags are implemented for high-risk or experimental features. Flags are toggleable via a control panel or configuration service without code redeployment.
- **Fail criteria:** No feature flags found, or flags exist but require code changes to toggle.
- **Skip (N/A) when:** The project is simple with low-risk deployments, or no high-risk features are being developed.
- **Detail on fail:** `"No feature flag library detected in dependencies."` or `"Feature flag library installed but no flags configured. Feature toggles require code changes."`
- **Remediation:** Integrate a feature flag service. Using LaunchDarkly (free tier) or Unleash (open source):

  ```bash
  npm install @launchdarkly/js-client-sdk
  ```

  Then in your app:

  ```tsx
  import { useFlag } from '@launchdarkly/react-client-sdk';

  export function MyComponent() {
    const newCheckoutFlow = useFlag('new-checkout-flow');

    return newCheckoutFlow ? <NewCheckout /> : <OldCheckout />;
  }
  ```

  Configure flags in the LaunchDarkly dashboard to toggle high-risk features without redeployment.

---

## External references

- iso-25010 reliability.maturity
- nist CM-3

Taxons: operational-readiness

HTML version: https://auditbuffet.com/patterns/ab-000979