Containers
Packaging an app with everything it needs so it runs the same everywhere.
Backend Engineer track
Junior
Write correct code, ship small changes safely, ask good questions.
Core: start here
- DockerThe most common tool for building and running containers.
10 more junior concepts
- ContainerA lightweight, isolated package of an app and its dependencies.
- Container LogsReading a container's stdout and stderr.
- Container RegistryWhere images are stored and pulled from.
- Container vs Virtual MachineSharing the host kernel vs emulating a full machine.
- Docker ComposeRunning multi-container setups from one YAML file.
- DockerfileThe recipe for building an image.
- Ephemeral Container FilesystemAnything written inside a container disappears when it's removed.
- ImageA read-only template that containers are created from.
- Port MappingExposing a container's port on the host.
- VolumePersistent storage that outlives a container.
Mid-level
Own a feature end to end without hand-holding.
Core: start here
- Multi-Stage BuildBuilding in one stage and shipping a small final image.
8 more mid-level concepts
- Bind Mounts vs VolumesMounting a host directory vs Docker-managed storage.
- Container NetworkingHow containers talk to each other and the outside world.
- ENTRYPOINT and CMDWhat runs when a container starts.
- Hot Reloading in ContainersSeeing code changes instantly while developing in Docker.
- Image Layers and Build CacheHow images are built from cached layers, and how to order steps.
- Image ScanningChecking container images for known vulnerabilities.
- Image Tags and DigestsNaming image versions, and why :latest is risky.
- Running as Non-RootNot running container processes as root.
Senior
Own a system, its failure modes, and its trade-offs.
- Minimal Base ImagesAlpine, distroless and scratch images for a smaller attack surface.
- OCIThe open standards for container images and runtimes.
- Union FilesystemStacking read-only image layers with a writable layer on top.
Staff
Shape how many teams build, across systems.
Nothing here yet.
Principal
Set technical direction for the organization.
Nothing here yet.
Data Engineer track
Junior
Build and fix pipelines from clear specs; write correct SQL.
- ContainerA lightweight, isolated package of an app and its dependencies.
- Container LogsReading a container's stdout and stderr.
- Container RegistryWhere images are stored and pulled from.
- Container vs Virtual MachineSharing the host kernel vs emulating a full machine.
- DockerThe most common tool for building and running containers.
- Docker ComposeRunning multi-container setups from one YAML file.
- DockerfileThe recipe for building an image.
- Ephemeral Container FilesystemAnything written inside a container disappears when it's removed.
- ImageA read-only template that containers are created from.
- Port MappingExposing a container's port on the host.
- VolumePersistent storage that outlives a container.
Mid-level
Own pipelines and models end to end, including their quality.
- Bind Mounts vs VolumesMounting a host directory vs Docker-managed storage.
- Container NetworkingHow containers talk to each other and the outside world.
- ENTRYPOINT and CMDWhat runs when a container starts.
- Hot Reloading in ContainersSeeing code changes instantly while developing in Docker.
- Image Layers and Build CacheHow images are built from cached layers, and how to order steps.
- Image ScanningChecking container images for known vulnerabilities.
- Image Tags and DigestsNaming image versions, and why :latest is risky.
- Multi-Stage BuildBuilding in one stage and shipping a small final image.
- Running as Non-RootNot running container processes as root.
Senior
Design the platform's storage, processing and modeling choices.
- Minimal Base ImagesAlpine, distroless and scratch images for a smaller attack surface.
- OCIThe open standards for container images and runtimes.
- Union FilesystemStacking read-only image layers with a writable layer on top.
Staff
Shape how the whole organization produces and uses data.
Nothing here yet.
Principal
Set data strategy and architecture across the company.
Nothing here yet.
Frontend Engineer track
Junior
Build UI that works, ship small changes safely, ask good questions.
- ContainerA lightweight, isolated package of an app and its dependencies.
- Container LogsReading a container's stdout and stderr.
- Container RegistryWhere images are stored and pulled from.
- Container vs Virtual MachineSharing the host kernel vs emulating a full machine.
- DockerThe most common tool for building and running containers.
- Docker ComposeRunning multi-container setups from one YAML file.
- DockerfileThe recipe for building an image.
- Ephemeral Container FilesystemAnything written inside a container disappears when it's removed.
- ImageA read-only template that containers are created from.
- Port MappingExposing a container's port on the host.
- VolumePersistent storage that outlives a container.
Mid-level
Own a feature end to end without hand-holding.
- Bind Mounts vs VolumesMounting a host directory vs Docker-managed storage.
- ENTRYPOINT and CMDWhat runs when a container starts.
- Hot Reloading in ContainersSeeing code changes instantly while developing in Docker.
- Image Layers and Build CacheHow images are built from cached layers, and how to order steps.
- Image Tags and DigestsNaming image versions, and why :latest is risky.
- Multi-Stage BuildBuilding in one stage and shipping a small final image.
Senior
Own an app's architecture, performance, and failure modes.
Nothing here yet.
Staff
Shape how many teams build, across apps.
Nothing here yet.
Principal
Set technical direction for the organization.
Nothing here yet.