PWABuilder is an open source project and builds cross platform web apps. We feel Medium is a better fit than the more corporate structured blogs. So far we've been pretty happy with Medium.
That said, we have been mulling building our own blogging platform using our own tools and web components for the sake of dogfooding.
You might want to customize it a bit more to make it clear this is an offical blog. For a few seconds when reading this on mobile I was super confused if this was official or just someone outside MS writing about it.
Thanks for this feedback. We're thinking about hosting a blogging platform directly under pwabuilder.com. We've got a small team that was mainly focused on writing new features & code but we definitely need to better address our blogging approach.
I don't think there's a public blogging software unless you count Sharepoint but I doubt that would scale well. Still Microsoft has a number of web products that could be used instead of Medium. A lot of the smaller Microsoft weblogs use Azure websites with Wordpress and the bigger ones are part of Micrsoft's in-house multisite.