[brainbag]

I am a longtime developer but I'm passionate about design and UX. I'm always on the lookout for materials that I can give my team and other developers to help them get better at design. It's not a course, but "The Non-Designer's Design Book" (ISBN 978-0133966152, Robin Williams) is the best material for design fundamentals I've found. It's very approachable for anyone and it's broadly applicable across all kinds of design. Everyone I have convinced to read it has loved it, and I've seen an improvement in output and understanding. I highly recommend this if you have an interest in design.

Refactoring UI is also valuable and can be impactful, though it's heavily web focused and is more like a Web Component Design Cookbook rather than foundational knowledge.