It was developed by Bebop, a company Google acquired last year for $380 Million that was founded by Diane Greene (Founder of VMWare). When Google decided to bring Diane Greene on full time to run Google Cloud, they had to purchase her company in order to facilitate that. Bebop originally had aspirations to shake up the enterprise software space by building a suite of applications, and the 'Hire' app was the first one they produced. Bebop employees have been working on it since then and had a long beta period before the launch today. As noted in the TechCrunch article, the 'Hired' platform also runs the Google for Jobs website that launched earlier this year.
http://fortune.com/2016/01/04/google-paid-380-million-for-di...