What candidates find out about employers before accepting a job offer

The process of selecting a new employee is by no means a one-way process. Especially today, when companies are fighting for quality employees, it is the employees who select their employer. And thanks to the Internet and modern technologies, they are now able to learn more than ever about the true state of things at a particular workplace. For instance, there are platforms that serve as databases of employees' reviews about employers. What do potential employees look for in advance concerning their future employers and what information about your company should you be concerned about?