In cram school-obsessed South Korea, students fork out for classes in everything from K-pop auditions to real estate deals. Now, as top Korean firms roll out artificial intelligence in hiring, job seekers want to learn how to beat the bots.

From his basement office in downtown Gangnam, career consultant Park Seong-jung is among those in a growing business of offering lessons on how to handle recruitment screening by computers instead of people. Video interviews using facial recognition technology to analyze character are key, according to Park.

"Don't force a smile with your lips," he told students looking for work in a recent session, one of many he said he has conducted for hundreds of people. "Smile with your eyes."