That used to involve putting film or paper into a chemical bath. You could have a small influence over what happened, but almost all the work involved setting up the shot in the first place. The goal of the bath was to uncover what was already on the film.
Developing today has a totally different meaning. We’re not simply uncovering, we’re building. Software, careers, our culture–we develop them daily, adding a little bit at a time, toward the future we seek to create.