To ensure tight synchronization between the frontend and backend, the MSC platform was built as a monorepo orchestrated by Nx. This structure housed the Next.js application (`apps/web`), the NestJS API (`apps/api`), and a shared library for types and Data Transfer Objects (`libs/types`). This decision established a 'Single Source of Truth'. Any change to an interface or DTO in the shared library immediately alerted both the frontend and backend compilers. While managing path aliases and dependency versions required initial discipline, Nx's intelligent caching and unified command execution (`nx run-many -t lint test build`) vastly accelerated our CI/CD pipelines in GitHub Actions, preventing contract mismatches in production.