Hi all! 
We’re excited to announce that Temporal Worker Versioning is in public preview! This feature has been fine-tuned to meet the needs of our users and add more functionality, so we’re pumped to share it with you.
Worker versioning allows users to safely deploy new updates to Workflows already running without breaking them, and allows users of blue-green or rainbow deployments to:
- Ramp traffic gradually to a new Worker Deployment Version
- Verify a new Deployment Version with tests before sending production traffic to it
- Instantly rollback when you detect that a new Deployment Version is broken
This release also introduces Workflow Pinning. For pinned Workflow Types, each execution runs entirely on the Worker Deployment Version where it started - so users don’t have to worry about making breaking code changes to running, pinned Workflows.
As part of this Worker Versioning release, we will be spending this summer adding features, docs, and code samples that give you more direct, programmatic control over your deployments.
Join the conversation on our community Slack in the channel #safe-deploys.