Pros
Reasonable hours and not much overtime expected because of contract. Benefits are standard, but nothing above and beyond what other companies offer. They seem to hire pretty good employees overall, but then they don't seem to know what to do with them after they have them. Look for a long established team not one of the ones only in place for a few years.
Cons
Big communication problems dependent on what team you are on. Check carefully before accepting position. Extremely high turnover on certain teams with employees jumping ship. If you have a bad or unclear vibe from the beginning, your gut is probably right. When it comes down to it, individual manager ethics are very questionable and it will be every man for himself. Not a good situation when working in sensitive areas of government. Pay is not anything to write home about either.
