Waze cofounder explains the test he uses to figure out whether to fire a new employee — and how it can be used to figure out if you should switch jobs

Waze's cofounder asks, "Knowing what I know today, would I still hire this person?" If the answer is yes, he gives them more equity to keep them loyal.

• Waze's cofounder said underperforming employees drive away top performers and can harm a company.
• Cofounder Uri Levine said he uses a 30-day test to determine if he should fire a new employee. 
• He said a similar test can be used for other things in life, like relationships or career paths.

Waze cofounder Uri Levine has founded 10 companies, served on the board of 20, and advised more than 50 — and he believes underperforming employees can be a liability to a startup.

Levine said on an episode of "Lenny's Podcast," released Sunday, that when there are people who shouldn't be on a team, top performers leave. Then, it becomes "mission impossible" to achieve success.

That's why Levine likes to cut to the chase when it comes to firing, as he detailed in his new book "Fall in Love with the Problem, Not the Solution: A Handbook for Entrepreneurs." In his chapter about firing and hiring, he said in the interview that he implemented a 30-day test to determine whether to fire a new employee.

The test involves marking his calendar 30 days after the person starts the job. Levine said once it hits the 30-day mark, he asks himself, "Knowing what I know today, would I hire this person?"

If the answer is yes, he suggests reaching out to the employee immediately, giving them more equity in the company, and buying "their loyalty for life." If the answer is no, he said the employee should be fired immediately.

"They're already set on a trajectory of not being successful," Levine said. "And they are creating damage to you, to the rest of the team, and to themselves."

Levine said the employee deserves to be successful, but in this hypothetical case, it's not going to happen there. The test prevents a situation in which a team faces long-term issues that came from a single employee and were clear out of the gate. Levine said this was often the case when he spoke with entrepreneurs whose startups failed.

Levine said that's part of why he named one of his book chapters "Firing and Hiring" instead of the reverse. The cofounder said CEOs need to learn how to make hard decisions before easy ones.

Waze did not immediately respond to Business Insider's request for comment ahead of publication.

Levine said this test can be applied to "everything in your life," including relationships and directions you're going in life.

"Ask yourself, knowing what you know today, would you do something different? If the answer is yes, then do something different today," Levine said. "Today is the first day of the rest of your life."

The cofounder said he has five children in their 20s and early 30s, and they struggle with figuring out their career paths. He said he tells them to ask themselves why they don't like their jobs and if they can change something. Levine said he would follow up in 90 days, and if it's still the case, they should quit.

"If you don't set a timeline, it'll never happen," Levine said.