Digital Monitoring of Employees

This Marketplace story describes some of the ways that employees can use devices to monitor digitally what the employees are doing: http://www.marketplace.org/2017/02/22/world/meet-workplace-sensors-are-watching-you.

1. How could an employer assess digitally the traits of job applicants to determine which ones to hire?
2. How could an employer monitor digitally what employers are doing or producing to determine which ones to reward monetarily or to promote?