Advanced everything in Docker & Kubernetes, page 5
Container Runtime Shim: Decoupling the Container Lifecycle
A runtime shim is a small process that decouples the container daemon (like containerd) from the container itself. This lets the daemon restart without killing running containers.
OCI Runtime Spec: The 'How to Run' Standard for Containers
The OCI Runtime Spec is the universal instruction manual for executing a container. It defines a standard config.json and lifecycle actions, ensuring a container runs the same way across different runtimes like runc or crun.
Union File Systems: Docker's Layered Magic
A Union File System stacks read-only layers and adds a writable one on top, like transparent overlays. This lets containers share base images, saving disk space, while isolating changes via copy-on-write. The footgun is performance on write-heavy apps.
We are hiring for this. Every open role lists the topics its interview covers, so you can prepare for the real thing rather than guessing.
See open roles