For the third year in a row, consulting firm McKinsey & Company has been rated as having the most difficult interviewing process by employees.Glassdoor's ranking placed McKinsey at a 3.9 difficulty rating out of 5.0, beating out tech giants like Google and Facebook, which were also in the top 25.

The average interview difficulty rating on Glassdoor is 2.8.

Newcomers to this year's list include BlackRock, Microsoft Citrix, HubSpot, and Vistaprint.

Some companies still ask crazy brainteasers, despite Google's claims that they have nothing to do with success, while others stand out for running candidates through lengthy tests and round after round of interviews.