System Design FAQ: Top Questions

A CI/CD Pipeline System automates the build, test, and deployment of code to production or staging environments. It supports faster iterations, higher reliability, and rollback in case of failure.

📋 Functional Requirements

• Trigger builds on code push (webhooks)
• Run unit/integration tests and static code checks
• Deploy to multiple environments (dev, staging, prod)
• Support rollback and version tagging

📦 Non-Functional Requirements

• High availability and idempotent builds
• Artifact retention and caching
• Secure secrets management

🏗️ System Components

• Source Control: GitHub, GitLab, Bitbucket
• CI Engine: Jenkins, GitHub Actions, GitLab CI
• Artifact Store: Nexus, Artifactory, S3
• CD Engine: ArgoCD, Spinnaker, Flux
• Secrets Store: Vault, KMS, SOPS

⚙️ Sample GitHub Actions Workflow

name: Build and Deploy

on:
  push:
    branches: [ "main" ]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Build app
        run: npm run build
      - name: Run tests
        run: npm test
      - name: Push Docker image
        run: |
          docker build -t myapp:${{ github.sha }} .
          docker push myapp:${{ github.sha }}

  deploy:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - name: Deploy to Kubernetes
        run: kubectl apply -f k8s/deployment.yaml
        

🔐 Secrets via GitHub

• Use GitHub Secrets to store DOCKER_USERNAME, K8S_TOKEN
• Mounted via secrets. in workflows

📦 Artifact Handling

• Store JAR/Docker/tar files in Nexus or S3 with versioned tags
• Use caching to reuse dependencies between builds

🚀 Deployment Strategies

• Blue/Green: Route traffic only after new deployment is verified
• Canary: Gradually increase traffic to new version
• Rollback: Auto-revert if liveness/readiness probe fails

📈 CI Metrics to Track

• Mean time to build
• Deployment frequency
• Failure rate / rollback frequency

📌 Final Insight

A CI/CD system enforces best practices via automation, minimizes human error, and ensures rapid iteration. Use config-as-code for reproducibility, and tightly control credentials and access.