Pros
Work on mega projects that really move the needle. Salary is above average, and get paid straight-time overtime. Can pursue whatever work interests you. Remote as needed. Incredibly diverse. Work life balance is great. 9-5, no OT if you don't want it.
Cons
Can be slower at times, upper management does shift around depending on group. Mostly federal or government projects, private developers are too risky for AECOM to have interest in pursuing. No koolaide or culture whatsoever. It's a con because I've been in this office for over a year and the other day another engineer walked by me and was like "hey are you xxx?" and I said um no I'm xxxx I've been working 10 feet away from you for over a year? That basically sums up the culture. Everyone kinda does their own thing.