Communications of the ACM

As soon as Tom Smith got his hands on Codex — a new artificial intelligence technology that writes its own computer programs — he gave it a job interview.

He asked if it could tackle the "coding challenges" that programmers often face when interviewing for big-money jobs at Silicon Valley companies like Google and Facebook. Could it write a program that replaces all the spaces in a sentence with dashes? Even better, could it write one that identifies invalid ZIP codes?

It did both instantly, before completing several other tasks. "These are problems that would be tough for a lot of humans to solve, myself included, and it would type out the response in two seconds," said Mr. Smith, a seasoned programmer who oversees an A.I. start-up called Gado Images. "It was spooky to watch."

Codex seemed like a technology that would soon replace human workers. As Mr. Smith continued testing the system, he realized that its skills extended well beyond a knack for answering canned interview questions. It could even translate from one programming language to another.