IBM Plex is the most ambitious design system project I have been a part of. IBM had been paying an arm and a leg to use Helvetica Neue, but the Brand Team was on a mission to create a new typeface that was distinctly IBM.
I was asked to help figure out the best strategy to distribute the new typeface to designers and developers across the company. That's a lot of people (~400,000) using the typeface on different operating systems, programs, and code bases. It is also worth noting how rare people are used to installing their own font files!
I ended up strongly advocating that we standardize Plex releases in an open-sourced project. This made it easier for employees to find the typeface outside of IBM's intranet and also came off as a strong goodwill gift to the tech industry. Our repository hosts the source files and then distributes related CSS for typeface fallback suggestions.
There was also a constant complaint about the performance cost of our older Helvetica Neue files on web projects. We ended up collaborating with the Google Fonts to publish the typeface to their servers for faster delivery. The Google Fonts team also helped advise us on how to break up the large font files by segments of commonly used characters.
Like the typeface this page uses? Cool, you're looking at IBM Plex!