petralithic parent
If you're an employee at some company you can post about your own work too on your own blog. The fact that he maintains the hosting platform as well doesn't mean much, 37Signals employees can post on Medium or some other blog host too.
If I post something on my personal blog, and it's against the company's Code of Conduct, then I'm in trouble with HR. If I'm the company's CEO, then I'm in trouble with the board. You're not an island.
Then you'll just have to be a CEO with a platform. And if it's on your personal blog, I don't see why you'd be in trouble with HR at any good company, unless they're monitoring your communications.