THE GREAT DIVIDE

There are two ways to compute, and two ways to see the world. It's batch vs. loopand we really need them to reconcile

EVERY FEW MONTHS we get to see a tech dude offer excruciating testimony to grumpy members of Congress. The tech dude tries, with varying degrees of arrogance, to explain his world; the congresspeople recite their questions; in the end, no one seems notably changed by the experience. There are many ways to understand these interactions-East Coast versus West Coast, lawyers versus engineers, political narcissists versus corporate narcissists-but I think the core conflict is between batch culture and event loop culture.

In the beginning of computing, batch processing reigned supreme. You would gather your stack of punch cards, wait in line for your turn at the giant electronic brain, feed it your data and instructions, then wait minutes or days for its digital gears to grind out a response. Each batch had a discrete Before and After: You did a thing, the computer did a thing, you went back to gathering punch cards. Then came the event loop: The electronic brain-now small and affordable enough to sit on your desk!-would wait for you. You would do something (type a key, press a button, or later, click a mouse) and it would respond, right there in the moment, painting a letter on the screen or starting up a video.