A talk about what I call Progressive Delivery: a basket of skills and technologies concerned with modern software development, testing and deployment: including canarying, Feature Flags, A/B testing at scale. We're seeing Advances in approaches to application and service. On the technology side, Kubernetes and Istio bring new management challenges, but also opportunities – service mesh approaches can enable a lot more sophistication in routing of new application functions to particular user communities, managing and mitigating the blast ratio of a service.