The microfrontend architecture with the webpack module federation could be critical when it comes to integrate old legacy cra apps together. The monorepo architecture is a nice solution when you have multiple apps that needs to share common rules (eslint, code conventions, etc etc) without becoming monoliths
Here we have simply different cra apps (packages/a, packages/b, packages/container) handled by Lerna, and transpiled by babel that uses the same config at the project root
You can simply navigate to the single app, for example:
cd packages/a
npm i && npm start
You can simply do:
npm run installation && cd packages/container && npm start
Super easy config files (only babel and lerna), that's all
Let's have a look about how the final result by visiting it's demo