What in tarnation. For 100 bucks/month you can get 1-1 mastery learning sessions from math PhDs/postdocs that need money (like me! I am the postdoc!).

If you want to learn some math and are willing to fork over $50 a month, my advice is to find a competent tutor online*, tell them what your goals are, and work with them to produce an evolving, customized mini-course.

Have them pick material suitable for your goals, work through it in-session together so they can spot gaps in your knowledge/technique and make progressive problem sets to cover those gaps, and so on.

*A local tutor would be better, but I presume they will be prohibitively expensive in the average HN user's location.

> For 100 bucks/month you can get 1-1 mastery learning sessions from math PhDs/postdocs that need money (like me! I am the postdoc!).

But how many hours of tutoring will 100 bucks/month get me? Maybe 1 hour per week.

No, you can't do anything in 1h/week, 3 hours should be the minimum, 4 is ideal, depending on the level of the class (I would ask for more than 100 for 4 hours a week if I am to teach advanced harmonic analysis, for example).

The problem is that finding a postdoc that is also a good _teacher_ is a monumental task of its own.

Compared to an online platform that's being used by a ton of people, has lots of reviews and recommendations and that is, presumably, actively optimized through a feedback loop, it's an easy choice between the two. Also, a platform removes the friction of cancelling the engagement if the need to do so arises for whatever reason.

I mean, if someone I know points at a postdoc and says "this guy is excellent", then their recommendation will prevail. But chances of that happening are next to zero.

I have no experience with those platforms, so I don't know how deep the instruction is. After taking, say, a Calculus course there, would you be comfortable doing Spivak's exercises? If yes, that seems great.

This is orthogonal to the instruction quality. What good is the depth of the material if the teacher can't explain it clearly and concisely?