You want to turn on a feature for 10% of users without redeploying. What fits?
Why C is the answer
A feature flag
Feature flags change behavior at run time, without a deployment.
In detail
- A feature flag can target a share of users, with no deployment.
- Remove flags once a feature is fully live.
Use case
An illustrative scenario, not a real incident.
A team turns on a new checkout for 10% of users with a feature flag, watches it, and turns it off at once if needed.
See it in different ways
sequenceDiagram participant A as App participant C as App Configuration participant V as Key Vault A->>C: Reads settings and flags C-->>A: Key Vault reference A->>V: Reads the secret, with its managed identity V-->>A: Current value
flowchart LR S0["Deploy with the flag off"] --> S1["Enable for 10%"] --> S2["Watch"] --> S3["Enable for all"]
Key point: Feature flags change behavior with no deployment.
Why the other options are wrong
- A. A second Azure subscription
- A subscription is not a way to target users.
- B. A new Key Vault for that feature
- Key Vault holds secrets.
- D. A new container image for those users
- That is a deployment.