Progressive delivery is a software deployment approach that minimizes risk by gradually releasing new features to subsets of users, allowing for performance monitoring and rapid rollbacks. Key strategies include canary releases (testing on small groups), feature flags (toggling features), and blue-green deployments. This methodology focuses on reducing blast radius and utilizing automated, data-driven feedback loops to ensure stability.

Key Progressive Delivery Strategies
Canary Releases: A new version is deployed to a small subset of users (e.g., 5%) before expanding to the full user base, ensuring performance and stability.

Feature Flags/Toggles: Allows teams to separate code deployment from feature release, enabling instant toggling of features on or off without redeploying code.

Blue-Green Deployment: Two identical production environments ("Blue" for current, "Green" for new) are used to eliminate downtime; traffic switches from one to the other after validation.

Ring/Phased Rollout: Users are segmented into "rings" or groups (e.g., internal staff, then beta users, then 10% of users, etc.) for a controlled, phased rollout.

Dark Launches: New code is released to production but remains invisible or inaccessible to users to test infrastructure performance without user interaction.

Best Practices for Implementation
Automated Monitoring & Observability: Implement real-time monitoring to automatically detect issues and trigger rollbacks.
Automated Decision-Making: Use automated, data-driven gates to decide when to move to the next stage of deployment.
Controlled Audiences: Start with low-risk user groups (e.g., internal teams) before expanding.
Separation of Concerns: Separate deployment (the technical act of releasing code) from release (the business act of exposing functionality).