It can help. In the article, I recommend Nielsen "Seeing through a piece of mathematics", which is about exactly this. http://cognitivemedium.com/srs-mathematics

I think Anki helps build the necessary knowledge base to make such connections, but actually making those connections comes with putting that knowledge into practice.

> Spaced repetition doesn't seem to help learning how something relates to another logically like how to determine when to use what programming patterns.

You can make cards for those.

Of course, if you're making cards on those without understanding and internalizing, the cards won't help you.

Back at the uni days if I struggled to understand a math concept, proof or algo, I would just memorize it. After a while the understanding part would also come.

Yes you don't use Anki for understanding.

First you understand something, then you convert that understanding into flashcards so it sticks in your long-term memory.

Making connections is what matters for understanding. The Zettelkasten method has recently gained some traction for organizing and relating ideas. We've developed https://traverse.link/ as a way of building a Zettelkasten with spaced repetition

It's great for math, for example.

It's spacing + testing effect: https://en.wikipedia.org/wiki/Testing_effect

Suppose you can solve some problem or prove some theorem today. Then you try to do it again next week, next month and so on. It's very different from rote memorization.