[tdaltonc]

GitHub and Stackoverflow are interesting cases from a webfont perspective. They have the benefit that most of their users are repeat visitors that means they'll likely have the designers prefered fonts cached from a previous visit. They also both need to support EVERYTHING. Could you imagine the HN posts if they didn't? "Github doesn't support U+25C8! This crashed my Rust server, invalidated my identity, and made my grandparents cry!"

In that StackExchange post you linked to, they mentioned make their own branded web font. That's definitely what I would be advocating for if I were there. The case for Github making their own font is even stronger. Microsoft has a very good font team. Designing a family of brand fonts for GitHub would be a very cool project (How many brands care about their fixed width font as much as github?)