Canary release vs progressive delivery: Choosing a deployment strategy

The text explores two deployment strategies, canary release and progressive delivery, highlighting their methodologies, advantages, and complexities. A canary release is a deployment approach that gradually rolls out new software versions to a small subset of users to monitor performance and minimize risk, with the ability to expand to larger user segments if successful. Progressive delivery, on the other hand, is an overarching methodology that includes canary releases, feature flags, A/B testing, and blue-green deployments, providing granular control over feature rollouts and enabling the decoupling of deployment from release. While canary releases focus on system performance and are relatively simple to implement with basic traffic routing, progressive delivery requires sophisticated tooling and allows for feature-level control and user segment targeting, supporting nuanced testing strategies. Both strategies offer benefits in risk mitigation and data-driven decision-making, with canary releases being ideal for simple traffic splitting and robust monitoring, and progressive delivery being suited for fine-grained control and gradual user adoption. The text also discusses the implementation of these strategies in environments like Kubernetes, where tools such as Flagger and Argo Rollouts can automate the canary deployment process.