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 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.