[brancz]

Nobody is saying that a regular profiling tool can't detect it. However, it's one of those things that if you don't profile it regularly then these are easy things to miss. With a continuous profiler set up you skip everything regarding collection of the right data (and you can see aggregates across time which in the second example of the blog post was important because the memory allocations aren't necessarily seen in a 10s profile). It makes the barrier for including profiling data in your everyday software engineering way easier.

You can capture memory or CPU metrics with top as well, and that's useful, but it's not the same thing as a full-blown metrics system eg. Prometheus.

[nurettin]

How do you not profile something? It is right there on the call stack millions of times. Do you explicitly filter it? Do you forego the idea of profiling when something slows down the system?