Creating a basic monorepo setup that can get incremental updates to packages

Question

I would like to create a monorepo that uses very basic components (prefereably no Nx, Rush, Turborepo, etc)

I want to have an "app" e.g. created by create-react-app in the repo, and then some other miscellaneous components that are used by the app in separate packages in the monorepo

I have not found a way where the component packages can easily be incrementally recompiled without me manually going in and running the build on that individual component package though

I am looking at typescript "project references" to see if this can help, but I am not sure I have it fully wired up as I need. I don't yet have a command that has the incremental builds.

Example here https://github.com/cmdcolin/monorepo_template

Summary

• workspace-a - contains React components, depends on workspace-b
• workspace-b - contains React components, no dependencies
• app - a create-react-app instance, renders a React component from workspace-a

How can I make it so that when I have yarn start in the app directory, then changes to workspace-a or workspace-b will be auto-updated on the webpage? Adding another sub-command running in another window is fine also