I'd recommend courses by Stephen Grider (<a href="https://www.udemy.com/user/sgslo/" rel="nofollow">https://www.udemy.com/user/sgslo/</a>). I've been through some of his courses (React/React Native, Phoenix Elixir, Solidity). And all of them were very well documented, focused and accurate. Great stuff!
Not just on Udemy, but for MOOCs in general: <a href="https://news.ycombinator.com/item?id=16745042" rel="nofollow">https://news.ycombinator.com/item?id=16745042</a>
Anything by Peter Dalmaris such as <a href="https://www.udemy.com/arduino-sbs-17gs/" rel="nofollow">https://www.udemy.com/arduino-sbs-17gs/</a>