Mark Zuckerberg, the founder and CEO of Facebook, returned to Harvard University to get the degree he left behind when he dropped out nearly 12 years ago. At the age of 33, Zuckerberg is the youngest person to deliver the commencement address at the Ivy League university. And he used this opportunity to speak to his fellow millennials about the future.

The industry titan specifically told the graduates to prepare for automation to change the landscape of the job market and be there to change it for the better, according to The Chicago Tribune.

“You’re graduating at a time when this is especially important,” Zuckerberg said in the prepared remarks. “When our parents graduated, purpose reliably came from your job, your church, your community. But today, technology and automation are eliminating many jobs. Membership in communities is declining. Many people feel disconnected and depressed, and are trying to fill a void.”

How exactly does Zuckerberg want graduates to help support the economy? Working together on large public works projects, which could serve an entire generation the same way the Hoover dam or space program did for previous ones.

“To keep our society moving forward, we have a generational challenge – to not only create new jobs, but create a renewed sense of purpose,” he said. “So what are we waiting for? It’s time for our generation-defining public works. Let’s do big things, not only to create progress, but to create purpose.”