Software Engineering
How linear search actually works under the hood, why it costs O(n) no matter which built-in you reach for, and when sorting the data first to unlock binary search's O(log n) is worth the tradeoff.
Software Engineering
Which array operations are cheap and which aren't - why push and pop are O(1), search is O(n), and adding to the front or middle means shifting every element after it.
JavaScript
A working reference for how JavaScript actually schedules async work - tasks vs microtasks, and which Promise method (all, allSettled, any, race) fits which situation.
JavaScript
A working reference for JS/TS loops - which loop type to reach for, and the five different ways to iterate asynchronously without tangling parallel and sequential execution.