I just finished working for a Hedge Fund management company that 'merged' with a larger company in Denver. They were all Windows with 10 engineers (sys admin and developers) and we were LAMP and I was doing everything. At first, theirs was a typical response to that stack reacting like a deer in headlights and not wanting to touch it but then they decided that it was important to integrate the systems and get rid of the redundant IT (IE me). But since I ran everything and got tremendous results (employee of the month and such) their only option was to try and make me look bad so they tried to say it was my attitude and my emotional response to which I let them know I was bipolar and on medication and seeing a counselor regularly for several years and high stress situation (like mergers) made the condition worse and I was trying to correct for that but they needed to be accepting of a condition that is seen as a disability.
Long story short, both HR and upper management then colluded, ignored my requests and I documented everything and they were investigated by federal agencies. A year later, we settled through federal mediators for a years salary.
In the end, I found out that they were just a good old boys network and one person would protect the other to protect the other to protect the other. Lies upon lies upon lies to cover their asses. In talking to others, this is typical in finance. If this is something that you want and like in your employers, I say go for it. Otherwise stay far away.