Lack of upward mobility. There are no openings for promotion. They tend to hire from the outside for the more senior positions. From talking to my manager there was no way to get a raise without quitting. Seems like a broken policy.
Seemingly uncaring leadership. There are a ton of issues with customers strong arming us, site management not helping with anything, project managers don't make realistic schedules or take input, and many other systemic things.
Some groups are blaringly defective. Project management seem afraid to tell their leader the truth so they cover up problems by pushing us to do unrealistic efforts. The group in charge of the sorters have major quality issues that causes lots of travel and finger pointing.
Travel. It's fun and you learn a lot seeing the systems but it's exhausting because they don't have enough people to rotate you out when you're tired or sick.