Your Workloads Can Lose Some Weight: WebAssembly on Kubernetes

What if your container image were a few megabytes instead of hundreds of megabytes? WebAssembly (WASM) offers a radically lighter approach to running workloads on Kubernetes — right alongside your existing containers. In this talk, we'll dive deep into how WASM modules using the WebAssembly System Interface (WASI) integrate into Kubernetes through containerd shims like runwasi. Using a Rust example, we'll demonstrate the dramatic reduction in image size and startup time compared to traditional containers. We'll explore the current state of WebAssembly in the cloud-native ecosystem: what's production-ready today, and where you should wait before adopting. Beyond the basics, we'll look at real-world Cloud-Native Compute Foundation (CNCF) projects already running WASM in production and discuss the two areas where WebAssembly shines: plugin architectures that benefit from small, secure, sandboxed extensibility, and event-driven systems that can quickly scale from zero. Whether you're optimizing for resource efficiency or exploring new isolation patterns, this session provides insights into WebAssembly on Kubernetes and serves as a great starting point.