Engineering projects also have to deal with complexity, of course, but I think these tend to be more about complexity and can often be solved by "thinking it through" (which can be hard, though). How exactly are we going to interface to that other service? How can we deal with all that traffic? I'm not saying these questions are easy solve. Sometimes they are very hard, especially if the organization is large and the systems are complex. But for data science (and sometimes engineering, too), thinking it through is not enough. You need to do some work to figure out how to solve it.