Zero Downtime Deployments in the "Legacy" Context - A Real World Story

While zero downtime deployments seem to be a no-brainer in the containerized and cloudy world, lots of companies struggle to achieve this with "legacy" applications. Our international platform is a hybrid of a classical three tier JEE monolith and a modern microservices architecture. Yet we managed to establish automated downtime free deployments of the complete stack by applying techniques like service discovery, blue-green deployment and online DB deployments. I will talk about the challenges and respective solutions we implemented.