All keystrokes are recorded but that is not the main form of documentation created. A developer creates a playback of only the 'interesting parts' of the code and provides a narrative about why they think it is interesting.
Then, when someone looks at some unfamiliar code they can search to see if there is a 'story' about that bit of code. The code and the narrative playback side by side. The noise can efficiently be bypassed.
Then, when someone looks at some unfamiliar code they can search to see if there is a 'story' about that bit of code. The code and the narrative playback side by side. The noise can efficiently be bypassed.