The first strategy for progressive exposure is to use canary deployments. In a canary deployment, not all users are routed to the new version immediately – only a limited percentage of the users get access to that version. These users are the canaries and they are monitored very closely. If they experience any issues or if degradation in performance or a service is measured, the new deployment is quickly rolled back.

A typical approach to realizing canary deployments is to use them in combination with blue-green deployments. The difference is that instead of switching all users over at the same time, only a small percentage is moved over to the new version at the start, and then the number of users that are moved over is gradually increased over time. This might look something similar to the following:

If a deployment is rolled back because errors have been observed, this is not a fun experience for users. To prevent the same small group of users running into issues repeatedly, it might be beneficial to select a different group of canary users afterward.