Kubernetes Operators Demystified The Building Blocks That Matter Attila Mészáros

Kubernetes Operators are often described as “just controllers with custom resources”—but building one that works reliably in production requires understanding the underlying mechanics. In this talk, we’ll explore the core building blocks of Operators using the Java Operator SDK and Fabric8 Kubernetes Client. We’ll cover informers and caching, reconciliation loops, and why events aren’t always as reliable as expected. We’ll also dive into practical challenges: watching across namespaces, filtering, retries, rate limiting, and lifecycle management with finalizers. Finally, we’ll discuss scaling strategies, including sharding and autoscaling Operators. This session is for engineers who want to go beyond basics and build Operators that are predictable, efficient, and production-ready.