My personal mantra (that I myself cannot uphold 100%) is that every dev should at least do the exercise of implementing binary search from scratch in a language with arbitrary-precision integers (e.g., Python) once in a while. It is the best exercise in invariant-based thinking, useful for software correctness at large
Yes, it's a simple enough algorithm to be a good basic exercise---most people come up with binary search on their own spontaneously when looking a word up in dictionary.
