Google exec shares his No. 1 strategy for mapping out your career

Peter Roper became an executive at Google in part by repeatedly asking himself one question: "What skill set can I develop to enhance my career?"

Before becoming head of mobile brand strategy at the search giant in 2014, Roper made a point to prioritize new job opportunities not by the salary or location, but by the skills he would acquire.

It's a strategy that set him up for success.

Roper, who spoke with CNBC at the Millennial 20/20 conference on March 1, held several jobs in advertising, sales and technology — including director of ad revenue strategy for music start-up Songza, which Google later acquired.

While his job at Songza was markedly different from the one he would later land at Google, the unique combination of skills he gained made him the perfect candidate for his next role.

"The reality is we're all going to switch jobs a lot of times during our life and you have to have a longer term plan," Roper says.

"You don't have to have your career perfectly mapped out," Roper says, "but thinking of it in terms of chunks of expertise and specialty that you'd like to obtain along the way is a great way to make sure that your moves are building on each other."

Before you take any job, or decide to leave your current one, the exec recommends you concentrate on the skill set you want to gain next.

"Envision yourself at the company for two or three years," he says. "What skill set will you have now that you don't have when you started that job? And where is that going to take you?"

Check out a former Google career coach's visual trick to figure out what to do with your life

Video by Zack Guzman.