What are some of the good online courses that I can take, to expand my knowledge with UX/UI design? I know this is a broad subject, but suggestions on a good course to get me started would be great.
I could not recommend more the Nielsen Norman Group seminars. NNG is the very high top UX consulting agency. Since the beginning of the lockdown they switched (very effectively) to online format now.
I've been attending their offline and online courses for over 3 years now. Can't stress enough how insightful the classes are. Check it out!
Particularly for a software developer that would like to know more about UX (kudos for that btw) I would recommend their Lean/Agile UX seminars or anything you can find useful in their seminars offering.