How do you build a robot army?

Depictions of the future in books and film are usually influenced by what's going on at the time, reflecting social malaise, impending armageddon, or economic anxieties. The robots in classic sci-fi usually resembled humans, as most authors assumed they would eventually assist us in the same tasks humans did. Instead, however, today we find artificial intelligence doing some of our thinking for us, but it's more often solving problems that don't need intervention from self-contained humanoid robots. The promise of autonomous robots that matched our abilities has given way to a more specific focus on tasks that are fulfilled by armies of smaller bots controlled by machine learning and algorithms running in the cloud. Their scope is more complex, but a lot less dramatic than, say, Forbidden Planet's Robby the Robot, or the replicants from Blade Runner.