This is such a weird article, not only it seems like it's the company itself trying to glaze themselves in third person, but claiming that it's a single line of change when they're swapping out a library feature is just disingenuous; you also don't need sophisticated tooling to find an unoptimized hotspot, perf record would suffice.
I mentioned this on another thread as well, but the point isn't that perf can't catch something like this, but it's that having continuous profiling set up makes it way easier to make profiling data an everyday part of your development process, and ultimately nothing behaves quite like production. This allows things that gradually sneak into the codebase to be easily spotted since you don't have to go through the whole shebang of getting representative production profiling data over time, because you just always have it available. Continuous profiling also allows you to spot intermittent things easier and so on.
(disclaimer: I'm the founder of the product showcased in this case study.)
