Back to Blog
DevOps10 min readFebruary 20, 2026

CI/CD Pipeline Architecture Explained with Diagrams

Visual guide to CI/CD: build → test → deploy stages, tool choices, and pipeline topologies for modern teams.

What is a CI/CD pipeline?

A CI/CD pipeline automates the journey from code commit to production deployment. Continuous Integration (CI) merges and tests code frequently; Continuous Delivery/Deployment (CD) releases validated code to staging or production automatically.

The goal: reduce lead time from days to minutes while maintaining quality through automation.

Pipeline stages

1. Source

A commit or pull request triggers the pipeline. Git hooks, webhooks, or polling mechanisms detect changes. Most teams use GitHub, GitLab, or Bitbucket as the source provider.

2. Build

Compile code, resolve dependencies, build Docker images, bundle frontend assets. Artifact registries (ECR, GCR, Artifactory) store the output. Build caching dramatically reduces iteration time.

3. Test

Unit tests catch logic errors; integration tests verify service interactions; end-to-end tests validate user flows. Code coverage gates and static analysis (SonarQube, Snyk) prevent regressions.

4. Deploy to staging

Automated deployment to a staging environment that mirrors production. Canary deployments or blue-green switches reduce blast radius. Smoke tests validate the deployment before promoting.

5. Deploy to production

Feature flags, progressive rollouts, and automated rollbacks ensure safe production releases. Monitoring (Datadog, Prometheus) alerts on error rate spikes post-deploy.

Build your architecture diagram now

Datadef generates professional diagrams with AI — 2,000+ cloud icons, column-level data lineage, and an MCP server your coding agent can drive.

Try free — no sign-upAI Diagram Generator

Popular CI/CD tools

  • GitHub Actions — YAML-based workflows tightly integrated with GitHub. Free tier is generous for open-source.
  • GitLab CI/CD — built into GitLab with Auto DevOps, DAST, and container scanning out of the box.
  • Jenkins — the workhorse. Unlimited flexibility via plugins but requires significant operational overhead.
  • CircleCI — fast builds with Docker layer caching and orbs (reusable config packages).
  • ArgoCD — GitOps-based CD for Kubernetes. Declarative, auditable, and Kubernetes-native.

Pipeline topology patterns

Linear pipeline: Source → Build → Test → Deploy. Simple and easy to reason about. Best for monorepos and single-service projects.

Fan-out/fan-in: Run tests in parallel (unit, integration, E2E), then merge results before deploy. Speeds up feedback without sacrificing coverage.

Multi-environment promotion: Dev → Staging → Canary → Production. Each stage has quality gates. Used by teams with regulatory or compliance requirements.

Visualizing your CI/CD pipeline

A well-documented CI/CD architecture prevents "works on my machine" surprises and onboards new engineers faster. Diagram the pipeline stages, tool integrations, and environment promotion flow so your entire team understands the release process.