Authors fast, cheap, maintainable GitHub Actions workflows applying 2026 best practices: caching with `hashFiles` + `restore-keys`, parallelization via matrix + artifacts, reusability (composite actions for steps, reusable workflows for jobs), security (SHA-pinned actions, least-privilege `GITHUB_TO
Authors fast, cheap, maintainable GitHub Actions workflows applying 2026 best practices: caching with `hashFiles` + `restore-keys`, parallelization via matrix + artifacts, reusability (composite actions for steps, reusable workflows for jobs), security (SHA-pinned actions, least-privilege `GITHUB_TOKEN`, concurrency), trackable errors (named steps, step summaries, annotations, and stdout/stderr th