Deployment strategies: Types, trade-offs, and how to choose

A comprehensive overview of software deployment strategies covering big bang, rolling, blue-green, canary, A/B testing, shadow, feature flag, immutable, and GitOps-based deployments. Each strategy is explained with how it works, its trade-offs between risk and complexity, and when to use it. The guide also covers how to choose the right strategy based on five factors: downtime tolerance, infrastructure budget, team maturity, architecture type, and compliance requirements. Practical CI/CD pipeline integration examples using CircleCI, Argo Rollouts, and ArgoCD are included, along with best practices like automating rollback, separating deploy from release, and handling database migrations with the expand-migrate-contract pattern.