How we rewrote a production UI without stopping it

In this blog post, the author shares insights from a complicated migration process of a production UI for the Red Hat Hybrid Cloud Console, which involved rewriting a React application without downtime. The post details the architectural approach, including the use of behavioral specifications for regression testing, a bottom-up migration strategy, and the importance of maintaining a strict separation between versions. Key lessons include the need to specify behaviors before migrating, the enforcement of boundaries between versions using lint rules, and the continuity of building testing frameworks to ensure stability throughout the process.