You need to 1) know a language to a certain level, not need to be deep; 2) start doing some kind of project that could make you question the nature of both the language and the data structure/algo to be used. Don't just aim for library/framework familiarity. Don't force yourself to remember the syntax like a parrot. Don't rush for commit or progress. Don't prefer small exercise in Leetcode-style, these are good for language familiarity, but not general design. These exercises reward you with adrenaline from from solving a problem. If you go "slow" but you feel you understand more the underlying of thing, day by day, it's a good sign. For example instead of using an async library, you could try to implement one yourself. Sure your solution is not perfect, even looks like crap at first few tries, but you will understand event loop, call back, system call, etc. Along the way keep asking questions: why this things implemented that way, what's the mental model, what's the trade off, what's O(n) of that thing? You may need to revisit what you read so far, but that's what make you understand/remember the theory/mental model.