Ask HN: Oreilly Courses Recommendations

I have annual Oreilly subscription, and I want to make good use of it. I have found some good course content previously, but it's been little hard to find off late with lots of non tech content on the site. Does any one have recommendations for the courses they have enjoyed / liked which are technically hands-on. I am mainly looking for content on Python, Networking, Distributed Systems etc. Not looking for frontend/UI technologies.