One word: Management. Avoid working in IT Ops like the plague. Allow me to elaborate.
These "New Feature" projects are held in much higher regard than improving internal systems to streamline the chasm between Ops and Dev. The situation that results from this mentality is that DevOps has to support an exponential number of systems without any sort of automation to help maintain it. Point-click-point-click. No one knows how it was set up because documentation is non-existent. Be ready to ask about 3 other teammates to figure out how so-and-so set it up because you'll also be held accountable for maintaining this system, in addition to your regular projects. You're expected to spontaneously understand all the systems in an arbitrary amount of time after a short meeting where the speaker presents a series of mouse clicks, completely lacking any kind of automation or integration into existing systems. (Isn't this what DevOps is about?) There's no script, you'll just have to figure it out. If you don't finish your projects because of persistent production emergencies and offer this explanation, management doesn't listen and assumes that you're not up to the task in the project.
Get ready to be a perpetual firefighter in IT Ops. Management prefers to accept that fires in production are going to happen and that we have to deal with them, as opposed to looking for solutions to nip these issues in the bud. Additionally, you'll have to be on-call, and any work done while resolving production issues is not counted for overtime. If you are called in the middle of the night to resolve a production issue, you're expected to be in the office at the same time. As if nothing had happened. So you'll work for free, basically, with no flexibility. This is partially due to IT Ops management not setting expectations to middle management in Development as to the feasibility of new features, datacenters, or software systems they're planning on putting into production. IT Ops management just can't say no to new projects that come from upstairs that have practically immediate deadlines. Please at least delay new projects so Ops can catch up and resolve the other fires and urgent issues that have come up.
When you start in Ops, the first thing you'll get around 70 emails before even starting on any projects. The first twenty minutes is spent sifting through these emails to filter out forest fires from simple "Thanks Yous". To management's credit, the quantity of irrelevant emails was reduced from around a hundred overnight. You'll find yourself constantly watching your inbox for emergencies that pull you away from any project you're doing. This is no way to be productive if we're expect to complete an arbitrary number of projects per week. Management expects that emails take no time to go through and that you're working on your project without interruption. In an given day, you'll spend at least an hour sifting through irrelevant emails. This issue can easily be solved through simple communication with the other departments. This shouldn't be accepted as the norm.
Be ready for some serious favoritism in middle management. Even if something happened and you were simply doing that you were told by middle management, you'll definitely get the blame. Also, if there's an issue that needs to be addressed in terms of work performance, you'll only know by a written warning materializing on your desk with a list of issues (your complete responsibility or no) that you were never talked to about from the last 6 months. As if they are writing this all down as things happen. Even when trying to explain the situation or clear up some confusion, management won't listen as they have already heard middle management's side of the story, and that's all they need. It was your fault, just fess up to it.
There's a reason that most of the employees in IT Ops have been there for less than 3 years and that the turnover is incredibly high. On average, one employee left the team every month. The team is only comprised of 20 members. You'll be notified via mail if they let you go, rather than actually meeting with you.
The greatest shortcoming is management's refusal to recognize any of these as legitimate issues. If you believe anything different than they do, you simply "don't fit into their culture", no matter how separated from reality or how reputable the source of advice you are giving them.
