Hiring and firing isn’t cheap, especially for a startup, so make sure you make your mind up about your employees before the probation period is over. Think of it as an engagement period where both parties can quit before they’re in too deep i.e. married. And despite being able to sign a prenup in a real marriage, with employment there are always laws in place to compensate the employee in case of termination or quitting after the probation is over. A lot of them might even wait till the day after its over to quit so that they can cash in on benefits, which startups aren’t in the position to cough up so easily. So use it wisely, test them, figure them out, see their capacity to deliver, and attitude at work, don't wait till its too late.