Container Build Optimization: BuildKit, Layer Caching, Multi-Stage, and Build Performance

February 21, 2026

Cicd

Container-Build-Optimization, Dockerfile-Authoring, Ci-Pipeline-Design

Docker, Buildkit, Containers, Multi-Stage-Builds, Layer-Caching, Distroless, Kaniko, Ci-Optimization

Docker, Docker-Buildx, Kaniko, Ko, Jib

Container Build Optimization#

A container build that takes eight minutes in CI is not just slow – it compounds across every push, every developer, every day. The difference between a naive Dockerfile and an optimized one is often the difference between a two-minute build and a twelve-minute build. The techniques here are not theoretical. They are the specific changes that eliminate wasted time.

BuildKit Over Legacy Builder#

BuildKit is the modern Docker build engine and the default since Docker 23.0. If you are running an older version, enable it explicitly with DOCKER_BUILDKIT=1. BuildKit provides several capabilities the legacy builder lacks.

GitHub Actions on ARM64: Native Runners, Cross-Compilation, and QEMU Pitfalls

February 21, 2026

Cicd

Intermediate

Ci-Pipeline-Design, Cross-Architecture-Builds

Github-Actions, Arm64, Ci, Cross-Compilation, Runners

Github-Actions, Docker-Buildx, Qemu

GitHub Actions on ARM64#

ARM64 is no longer optional infrastructure. AWS Graviton instances, Apple Silicon developer machines, and Ampere cloud hosts all run ARM64 natively. If your CI pipeline only builds and tests on x86, you are shipping untested binaries to a growing share of your deployment targets.

GitHub-Hosted ARM64 Runners#

GitHub offers native ARM64 runners. For public repositories, these have been available since late 2024. Private repositories gained access in 2025. Use them with:

Multi-Architecture Container Images: Buildx, Manifest Lists, and Registry Patterns

February 21, 2026

Cicd

Intermediate

Multi-Arch-Builds, Container-Image-Management

Docker, Buildx, Multi-Arch, Arm64, Containers, Manifest

Docker, Docker-Buildx, Container-Registries

Multi-Architecture Container Images#

You can no longer assume containers run only on x86. AWS Graviton instances are ARM64. Developer laptops with Apple Silicon are ARM64. Ampere cloud instances are ARM64. A container image tagged myapp:latest needs to work on both architectures, or you end up maintaining separate tags and hoping nobody pulls the wrong one.

Manifest Lists#

A manifest list (also called an OCI image index) lets a single tag point to multiple architecture-specific images. When a client pulls myapp:latest, the registry returns the image matching the client’s architecture.