Ask HN: Resources to Self-study Mathematics from BS to MS level?

Hey HN community,

I've been looking to get deep and build my math skills from the foundation up. I have the time to dedicate to this endeavor and I'd love to hear if you have any specific resources/curriculums you recommend.

Something like https://www.susanjfowler.com/blog/2016/8/13/so-you-want-to-learn-physics would be ideal, but more focused on applied math.

One idea I had was to complete the MIT open courseware courses for the Applied and Pure math fields