Protiviti isn't really a consulting firm. The biggest red flag is that Protiviti is owned by Robert Half, a staffing agency. Let me make it clear, there is a very real reason Robert Half owns Protiviti and as time goes on Protiviti loses more and more of the little bit of independence the firm has from Robert Half.
Protiviti is in actuality, a staff augmentation firm. A good 70%-80% of the projects are just contractor type projects where you'll just be performing some small process for the client. Let me make it clear, on the overwhelming majority of the projects you won't be making recommendations or providing analysis or just generally helping the client improve, no you will be doing work for the client that they could hire a full-time internal employee to do but for one reason or another they need extra help. The worst part is that many of these projects are like quicksand (and I say quicksand because on many of these staff augmentation projects they won't let you move even if another true consulting needs a unique skill you have). These staff augmentation projects often have people stuck on the project for easily over a year (at which point it's like why even work for Protiviti when you can get a full-time job working for the client doing the EXACT same work).
Essentially working for Protiviti is like working as a contractor with the "title" of consultant
The projects are overwhelmingly garbage, and I would recommend everyone to stay away (unless you're interested in following the client's mind numbing processes). Things are really headed in the wrong direction and unless Protiviti cuts it's ties with Robert Half, the firm will just become another division of Robert Half.