I can only speak for the 'Strategy and Analytics' (aka 'S&A' or 'Data Sciences') group in Boston. But I imagine this is similar for other groups as well.
Management is completely incompetent and inept at doing their jobs. They constantly blame those lower than their level for their own idiotic mistakes.
Expect extremely long hours (minimum 50 hours a week), however usually much longer. They won't tell you this during the interview, but will instead tell you that "our team doesn't really have good work life balance" once you are already in the company and invested a lot of time to get there. Extremely deceiving.
In order to get people gullible enough to work here and to think this is a kind of work environment that is somehow acceptable, they almost only hire very young (early to mid 20's) and people who come from other countries who have no choice in accepting slave-like conditions as they may be sent home if they get fired.
NO appreciation whatsoever for hard work. You will kill yourself getting things done and then you will be treated like you are incompetent lazy trash. Management tries to motivate people by fear and threatening to fire you. They have no respect for their employees.
HUGE turnover due to their inhuman, mean-spirited, stupid, and incompetent management. I was there for less than a year but over half of the team I was with had left during that time. This is due to a combination of firings and people leaving in disgust. Somehow, management doesn't realize or take responsibility for WHY this is the case. Instead, they blame others and act dumbfounded for why they lose good talent.
Employees are expected to consistently match unrealistic deadlines with 100% perfection. Mistakes of any kind are grounds for termination, no matter how small. Management constantly requires perfection but at the same time tells you not to spend much time checking your work. They will then tell you how little time it would take them to do the same task ("you say 45 minutes to do that?? I can do it in 20!" (except not really)). The amount of stupidity is astounding as this is both unrealistic and fosters a toxic culture.
If you do decide to work at this hell hole, stay AWAY from the Dunkin Donuts team. You will thank me.