CI/CD Pipelines (Jenkins, GitLab CI, CircleCI)

Continuous integration & deployment: automate build, test, deploy

⬢ ティア 3テクニカル

+$20k-

給与インパクト

5か月

習得までの期間

普通

難易度

職種数

概要

CI/CD pipelines automate software delivery by connecting version control to infrastructure: code commit → build → test → deploy to staging/production. Hands-on skill (distinct from best-practices theory): GitHub Actions (most common), GitLab CI, CircleCI, Jenkins, Buildkite, Drone. Career progression: Practitioner (basic workflows, 3-5 months, $85-110k) → Intermediate (multi-stage, parallelization, matrix builds, $110-150k) → Advanced (blue-green/canary, OIDC secrets, monorepo optimization, $150-200k) over 5-6 months. Pricing: most platforms free ≤ X job-minutes/month; GitHub Actions $0.008/minute overages.

CI/CD Pipelines (Jenkins, GitLab CI, CircleCI)とは

CI/CD pipelines automate the journey from code commit to production: code is committed to version control, automatically built, tested, and deployed to staging/production without manual hand-offs. CI/CD eliminates the "works on my machine" problem and reduces deployment friction. Career paths: Practitioner (basic GitHub Actions/GitLab CI workflows, $85-110k) → Intermediate (multi-stage pipelines, parallelization, matrix builds, $110-150k) → Advanced (blue-green deployments, canary releases, OIDC secrets management, monorepo optimization, $150-200k+) over 5-6 months. Most modern teams use GitHub Actions (if on GitHub), GitLab CI (if on GitLab), or CircleCI. Jenkins remains dominant in enterprises. The skill is tactical and hands-on: you're writing YAML, debugging flaky tests, and optimizing build times. In 2026, CI/CD is foundational, teams without it ship slower and with more bugs.

🔧 ツール＆エコシステム

GitHub ActionsGitLab CI/CDCircleCIBuildkiteJenkinsDroneBitriseBitbucket PipelinesTravis CIAWS CodePipelineAzure DevOpsCodefresh

📋 始める前に

Git Version Control Shell Scripting Test Automation Frameworks

💰 地域別給与

地域	ジュニア	ミドル	シニア
USA	$95k	$135k	$185k
UK	£55k	£80k	£115k
EU	€58k	€85k	€125k
CANADA	C$105k	C$145k	C$195k

🎓 認定資格

GitHub Actions Certification GitLab Certified Associate AWS Certified DevOps Engineer - Professional HashiCorp Certified: Terraform Associate

🎯 CI/CD Pipelines (Jenkins, GitLab CI, CircleCI)を使う職種

⚖ 比較

Ci Cd Best Practices Devops Ci Cd Github Actions Advanced

❓ よくある質問

GitHub Actions vs GitLab CI vs CircleCI, which do I pick?

GitHub Actions: free inside GitHub (no API calls), YAML-native, 2,000 min/month free. GitLab CI: free tier includes 400 min/month, Docker-first, strong registry integration. CircleCI: 6,000 min/month free, best UI, strong community orbs. Jenkins: self-hosted, unlimited, oldest/most flexible but requires infra. Pick Actions if repo is on GitHub, GitLab if repo is GitLab, CircleCI for high-volume CI.

When should I use self-hosted runners instead of cloud runners?

Self-hosted when: (1) secret management critical (keys/certs stay on your hardware), (2) large artifacts (GBs per build), (3) long-running jobs (15+ minutes), (4) GPU/ARM hardware. Cloud runners fine for: web builds, tests, quick deployments. Cost crossover: roughly 100k+ minutes/month = self-hosted wins on cost.

How do I set up CI/CD for a monorepo?

Use path filters (Actions/GitLab) to skip jobs if certain folders unchanged. Example: only run backend tests if `/backend/**` changed. Use matrix builds to test multiple services in parallel. Avoid running 53 tests when only 1 changed. Tools: Nx, Turborepo, Bazel for smarter build graphs.

How do I pass secrets securely without exposing them in logs?

Use OIDC (OpenID Connect) tokens instead of static secrets where possible (GitHub Actions → AWS, GitLab CI → GCP/AWS). Mask secrets in logs (GitHub: automatic, GitLab: automatic). Never `echo $SECRET`, never commit .env files. Use vault/HashiCorp Vault for rotation.

How do I optimize build matrix and parallelization for speed?

Split by test type (unit/integration/e2e) and OS/Node version in matrix. Example: 3 OS × 5 Node = 15 parallel jobs instead of serial (15x faster). Use caching (node_modules, build artifacts). Reuse compiled binaries across matrix jobs. Measure job duration; move slow jobs first to finish earlier.

What's the best caching strategy to avoid rebuilds?

Cache by dependency lock file hash (package-lock.json/yarn.lock). Dependency changed → new cache key. Layer caches: build output, vendor, dist. Avoid caching everything, only cache what's expensive (npm install, build compilation). Measure cache hit rate; aim >70%.

Why do CI builds randomly fail without code changes, and how do I debug it?

Flakiness: network timeouts, race conditions, resource constraints, nondeterministic tests, time-dependent code. Debug: run locally with `npm run ci` (same steps), check logs for transient errors (timeout, 503), re-run 3x (true flake if 1/3 fails). Use test retries only as bandaid; find the root cause.