I was a front jack man in F1 back in the late 80s & early 90s. We were still using manual jacks then, not the pneumatic ones they use now. The job was to stop the car on its marks us much as possible, so sometimes getting a hit if the driver overshot or had brake problems. Then of course lift the nose, then it was my call to be sure that all four corners were done, then drop the car and get out of the way (we didn't have the cantilevered jacks they use now either - had to move quickly and hope some dumb cameraman or photographer hadn't got too close (knocked a few of them fair on their arse stepping back fast & hard to release the car over the years). The stop/go sign man then let the car go when the coast was clear - most times that was at the same time as I dropped the car. Back then we'd typically do a tyre stop in 5 seconds or just under.
No speed limits in pit lane back then - have a look at footage from back then of how hard the cars came in and left - really scary when compared to today, plus the pit lanes were more compact relatively (more cars) and there were a lot more people allowed in the lane back then.
In my view, whilst there is some truth about my role from back then being fearless (& requiring genuine strength & agility) I always considered all the roles to be pretty much equally the hardest, but each in their own way. My pal on the rear jack for example, had to step in behind the car, get the jack onto the jacking points and get the heavy end of the car in the air before the wheel guys started removing the wheels (the guns were on the nuts and hitting whilst the car was still on the ground). The 3 on each wheel each had a different job but none was easier or harder than the other in my view. The wheel guys nearest the fast lane were the ones in the most danger from other cars.
Took a genuine team, a whole lot of focus and practice, meticulous maintenance of the gear etc. Great to be part of and very easy to muck it up (which was rare but did happen) but it is amazing how much it all happens in slow motion when you're doing it all the time.