Vantaggi
AECOM has an emormous range of very experienced, knowledgeable engineers. AECOM wins large, exciting projects that give great exposure to junior engineers.
Svantaggi
AECOM as a business is incredibly disorganised and inefficient. The decision makers are generally quite out of touch with the workload and technical complexity of projects being worked on by their sub-teams. There is no standardisation of design workflow, and design reporting / calculation management is often scattered and inefficient. There is enormous pressure from above to "buy" jobs with very low fees, then complain when the business makes no money. Mentoring and development of junior staff is purely dependent on your direct manager, and can range from amazing to very poor. The pay is generally quite bad too.