In the evolution of Ruby on Rails monoliths with embedded React views, complexity often grows in hidden layers. Models leak across layers, JavaScript bundles bloat, and teams struggle with test sprawl and unclear boundaries. But there’s a middle ground between monolith chaos and full microservices.

By modularizing Rails backends into Engines and separating React logic into distinct, domain-scoped bundles, teams can gain clarity, testability, and long-term scalability; all while keeping the development speed of a monolith.