Everything Depends on Project You Are On
Pros
NTT DATA is enormous so take this with a grain of salt (This review is for Launch by NTT Data) - other sister companies might be different. Great project, great life. That's been the case for 2/3 projects I've been on. Lots of new things to learn on each project which is great for growth, although they tend to silo roles more than before. Unlimited PTO policy if you're grade 8 or above.
Cons
Negotiate salary hard upfront. Raises are scarce, low, and delayed. Usually have to wait 3 - 9 months to get your earned raise. This is likely NTT Data as a whole. Layoffs common at Launch. They are cutting great talent using the metric of 'billable' or 'un-billable' instead of rolling off the Bs and Cs to keep the As. Madness! The company struggles to acquire new business and has turned to bidding on price instead of value, so you'll likely be training your replacements at some point. Project/Client quality also taking a hit due to this approach.