Release Phase (Beta) | Heroku Dev CenterLast updated March 30, 2026 The release phase enables certain tasks to be run before a new release of an app is deployed. The release phase can be useful for tasks such as: Sending CSS, JS, and other assets from the app’s slug to a CDN or S3 bucket Priming or invalidating cache stores Running database schema migrations If a release phase task fails, the new release is not deployed, leaving the cur
