I recently switched to Linux and have been trying several open source projects. One of the applications I tried is a GTK3 application for RAW photo editing. However, while being quick at doing calculations in general, it has significant input lag. When clicking, dragging, or hovering it takes a noticeable time for the GUI to respond. As it is open source, I would like to spend some time and try to figure out if I can fix this. However, I am stuck at the first step. I do not know how to get frame profiling data for the program.

Thus, my question: How can I get profiling data for this app? I was considering using https://optick.dev/ however as GTK is event based, this does not seem to be the right choice.

Note: I need a solution for Linux and GTK3. However, I will award the solution to the answer which explains profiling for the most systems (Linux, Mac, Windows, ?) and GTK versions.