Pros
The people who work there are tremendous. A lot of effort is made to employee skilled, talented, and creative people who fit into the workplace culture and who are good to work with. IT doesn't always work, but they get it right more often than not. Great projects. AECOM still gets its hands on some of the really big project with lots of intersting and challenging opportunities. Good building. Good Career development courses, if you are choosen to go on these.
Cons
The systems are unruly, unweidely, and costly. Everything from time sheets and expense claims to managing a project is difficult and detracts from value. There is a certain level of stasis in such a big organisation that cannot be helped. You are sometimes promoted rapidly if you are good, but more often than not there are too many talented people for there to be a craer path to the top for everyone who starts as a graduate at AECOM. Tendency to allow 'deadwood' to linger and not push them out the door. Pay rates are not keeping up with market parity. A current tendency to hire senior staff and managment from outside which is frustrating some existing staff.