The monorepo vs multi-repo debate ran for over a decade without a clear winner. That wasn't because engineers couldn't agree — it was because both models offered genuine advantages under different constraints. A 50-person startup with three services and a 10,000-person company with hundreds of microservices faced different problems. The right repository structure depended on team size, deployment cadence, ownership models, and tooling maturity.
That calculus has changed. AI coding agents, code generation, and agentic development workflows have shifted what matters in a repository model. The repository model that gives AI coding agents maximum context, atomic cross-cutting changes, and transactional execution now has a clear advantage.
That model is monorepo.
The old tradeoffs were real
Before AI coding agents became mainstream, the monorepo vs multi-repo decision optimized for human workflows: how engineers navigate code, how teams draw ownership lines, how CI/CD pipelines scale, and how releases ship.
