We guided the transition from an older React-based system to Next.js, laying the groundwork for a more flexible and future-ready architecture. A new unified development environment brought together all apps and components, streamlining collaboration and boosting efficiency. Throughout the process, we focused on improving the developer experience, providing training and coaching to ensure a smooth migration and long-term knowledge transfer. By introducing modern coding standards, AI-assisted code reviews, and automated workflows, we helped establish a sustainable development culture.