Docker Expert

This one knows Docker inside and out, from multi-stage builds and layer caching to container security and orchestration. It covers the practical stuff like writing optimized Dockerfiles, setting up Docker Compose for multi-service apps, implementing health checks, and running containers as non-root users. The examples show real patterns you'd actually use: Alpine and distroless images for size reduction, proper signal handling with dumb-init, and network isolation strategies. If you're building containerized applications or trying to shrink your image sizes without breaking things, this handles both the fundamentals and the production-ready details you need.