Bitwit: Learn CS, logic, and math theory (_not_ DSA) with spaced repetition: https://bit-wit.com/

I was hit by a big wave of depression last year. That crisis gave me a couple of periods of hyperfocus, and I thought I might as well use them to try to improve my mind and my ability to reason.

I haven't had good results learning certain subjects, like CS/math, with Anki or other flash card systems. The only thing that ever seemed to work for me was doing a lot of problems with pencil and paper. But without problems exercising those tools or techniques, they tended to just evaporate from my mind.

So my idea was to combine spaced repetition and problem presentation, and create a system for generating problems and validating their solutions randomly and parametrically. So successive presentations of the same card would present a different problem... and the overall effect would hopefully be that you learn the invariants that each card is trying to present, instead of memorizing some combination of variables and values. Sort of MathAcademy but for CS.

I _think_ it's feature-complete at this point, though I'm still working on validating and publishing cards (and there are a couple of things I wanna do to improve security). I'm pretty early in the dogfooding process, and I'm still the only person using it, and there are definitely bugs. But if anyone would like to try it out, I'd be delighted to hear your feedback (email in profile, also on site). Just maybe go a little easy on me right now, lol :/

The Boolean Logic and Lambda Calculus subjects are free forever, and the first topic of each other subject is also free, so if you're intrigued you can use it for quite some time (literally months) before even needing to provide an email address. No need to pay for anything.