Currently we're using tsc with the new build mode to build everything at once, but the result is incredibly brittle and requires a lot of unnecessary extra configuration all over the place that tends to confuse people when they need to add extra packages or make changes somewhere. It's also very slow (hopefully something that will be fixed by tsgo, eventually).

My initial plan was to have a separate tsdown config in each package and use pnpm to build the entire monorepo (or at least, the parts necessary for each sub-application) in parallel. But your config also looks like a useful approach, I'll explore that as well. Thanks for sharing!