Monorepo vs. Polyrepo (Multi-repo): What’s the Difference?

A detailed comparison of monorepo and polyrepo (multi-repo) repository strategies, covering their definitions, pros and cons, and guidance on choosing between them. Monorepos keep all code in one repository, simplifying code sharing, atomic deployments, and standardization, but can suffer from scalability issues and complex CI/CD. Polyrepos split code per service, offering stronger isolation, fine-grained access control, and simpler per-project pipelines, but introduce coordination overhead and risk of code duplication. The post also clarifies common misconceptions (e.g., monorepos aren't just for small teams — Google and Microsoft use them at massive scale), provides a comparison table, and outlines decision criteria based on coupling, team autonomy, and security needs.