Even short haul can be a nightmare depending on route network and FTLs. While the UK still has some legal protection via CAP 371 the rest of europe already operates to EU-OPS FTL which allow up to 14 hour days with two pilots (or 11:45 through the night). Or even worse up to 18 hour days if you have a break in-between. The latter one is quite often used in short haul operation.
So it is quite legal to operate a flight from central europe to the west coast with just two pilots, or the same on the way back but the flight back starts in the evening which is even worse as it counts as having started at dawn since the home timezone counts for FTL calculation until you have been at the down route destination for more than 48 hours, which nobody can afford nowadays.
And on the short haul side a typical pattern would start at 5:00 with a three sector day landing around noon, followed by a minimum rest of 10 hours, then starting another 11:30 shift through the night, followed by minimum rest of 12 hours and then followed by a 5 sector duty after which you completely pass out. Do that for a whole summer accumulating 100 hours and around 250 duty hours a month and cumulative fatigue will get you in the end.