I'm a project manager for a ~60 person software dev firm. One project I'm on is with a large American enterprise, and the product owner and his direct manager are absolute assholes. I've got 8 developers that I try to shield from accusatory questions and extremely aggressive and borderline abusive behaviour. In the beginning we we all agreed not to take anything personally and to let it just roll off the back. We agreed to tighten up our processes and try to avoid confrontations by being super proactive with all our work, but we're coming close to the launch date, and it's getting worse as more pressure mounts. Ordinarily, we would have dropped the client by now and refused to put up with the end-justifies-the-means tactics, but unfortunately our company could not survive without this and a handful of other projects we have with this client. My company is actively looking for new clients so we are not beholden to this one, and my manager is apologetic and tries to run interference when she can, but I'm largely left to my own devices. This is a very high profile project that stands to disrupt its market. It's exciting for them and us. I have to maintain this relationship somehow. How do you manage your clients who are completely unreasonable, rude, and treat you and your staff extremely poorly?