title: How do code profilers work?
body: <p>While I was working on an University project, I used a project-internal profiler made by an elder student, it was very basic but good enough since its task was to subtract times between two points of the code and to give statistics. </p>
  
  <p>Now, how does a professional profiler work? Does it preprocess the code to insert checkpoints or stuff like that? Does it read the binary code with debug data to catch where a function is called?</p>
  
  <p>Thanks.</p>