CI/CD Pipeline Design

Design a comprehensive CI/CD pipeline for [Application Type: monolith/microservices/monorepo] deployed on [Infrastructure: AWS/GCP/Azure/Kubernetes]. Include: 1) Source control strategy — branching model (trunk-based vs GitFlow), branch protection rules, commit conventions, PR review requirements. 2) Build stage — dependency caching, parallel builds, build artifact management, Docker image optimization (multi-stage builds, layer caching). 3) Test stages — unit tests (< 5 min), integration tests (< 15 min), E2E tests (< 30 min), performance tests, security scanning (SAST/DAST/SCA), quality gates at each stage. 4) Deployment strategy — blue-green, canary, rolling update — recommend based on context. Feature flag integration, database migration strategy. 5) Environment promotion — dev → staging → production pipeline, environment parity, configuration management, secrets management. 6) Observability — deployment tracking, automated smoke tests post-deploy, rollback triggers, deployment metrics (frequency, lead time, failure rate, MTTR). 7) Pipeline optimization — identify bottlenecks, parallel execution, selective testing, incremental builds. 8) Tool recommendations — CI server (GitHub Actions, GitLab CI, CircleCI), artifact registry, deployment tools, monitoring integration. 9) Security — supply chain security, signed commits, SBOM generation, vulnerability scanning policy.