Pros
Flexible hours. The worker bees don't need to be in the hive 8-5, but they do need to be 98% billable. It's a massive, global company so a future interviewer might recognize the name, which could be good or bad.
Cons
Engineers are a number on a spreadsheet; a percentage of quarterly profits in a big "trickle down", pyramidal money making experiment. There is a pervasive anxiety, fear and distrust in the air, which may have something to do with unrealistic profit margins and insane billable hour ratios. Don't be fooled by the marketing. "Environmental" is an oxymoron. You are more likely to be working on a hydrofracking project than a windmill or solar plant. Since exceeding last quarters profit margins are driven by Wall Street, engineering project design quality tends to suffer, which for engineers is very dissatisfying. Lump sum projects are popular. Typical design project margins are anywhere from 5-15% at most reputable engineering firms, but you are expected to hit the 25-30% mark.