"Every perception is to some degree an act of creation, and every act of memory is to some degree an act of imagination."
-- Gerald Edelman, Second Nature: Brain Science and Human Knowledge
4 Appendix 2: Using Anki to learn APIs6 Appendix 2: Using Anki to learn APIsAppendix 2: Using Anki to learn APIsAugmenting Long-term Memory2020-09-24Journal
The overall process is much like the common learning-by-doing approach to a new API, where you gradually learn the API through repetition, while working on a project. The main difference is that the occasional interspersed use of Anki considerably speeds up the rate at which you agglomerate new knowledge.
A potential failure mode is to think “Oh, I might want to learn such-and-such an API one day, so I should start adding cards, even though I don't currently have a project where I'm using the API.”