How do you build a unified product from a stack of open-source tools? In this talk, a Cozystack core maintainer walks through the engineering journey of integrating Helm, Operators, and the Kubernetes Aggregation Layer to build a general-purpose API—without using etcd. Discover how they built a dynamic API server, a universal GUI for operators, and a real-time billing system using Prometheus. A deep dive into platform engineering and the practical challenges of building open-source cloud platforms.