Rush build delivers a powerful cross-project incremental build. Also, if you only want to work with a few projects, you can build only the subset of packages you are interested in.
When it's time to do a release, Rush can detect which packages have changes, automatically bump all the appropriate version numbers, and run npm publish in each folder. If you like, configure your server to automatically run rush publish every hour.
Rush was created by the platform team for Microsoft SharePoint. We build hundreds of production NPM packages every day, from internal and public Git repositories, for third party SDKs and live services with millions of users. If there's an important package management problem that needs solvin', it's likely to end up as a feature for Rush.