I design a lot of administrative interfaces, and they pose a different challenge. Usually, a small number of people will use them many times a day (aka power users). So the efficiency to gain is to tailor the experience and make it as fast as possible, even if it requires some training. The information density is often higher, and the microinteractions matter. Things like tab order, keyboard shortcuts, abbreviations, color coding and data visualization often factor into the equation.
A huge upside for this work is I usually have direct access to these power users, and I can iterate work with their feedback at every step. It’s pretty satisfying for everyone, because they are intimately involved in deciding how the experience should be.
They often can’t wait to get their hands on it, which is satisfying for me!