I have 3 regular group rides I do (not all 3 every week but at least 1 every week in the summer). All 3 are fairly predictable in terms of where we go hard and where we take it easy. In terms of “analysis” which may be overstating things a bit as it is not as detailed as it sounds. I use TrainingPeaks and a little Strava.
Overall I’ll look at TSS and Kjs to gauge how hard the overall effort was. I also make some notes on how I felt and any highlights. Things like how fatigued was gong in, was i super hot or windy, did the young stud cat 1’s show up so it was unusually hard, etc. I’ll look at my peak power for various times (5 min, 1 min etc). The hard parts of all these rides are segments on Strava so I’ll look at my performance on the key segments relative to my prior performances. I often will have a specific set of goals for the ride in mind so I’ll also look at whatever data I have to see how i did on those.