25 Toughest Companies To Interview With

How many uses for a brick could you come up with in a minute? Now imagine that you're being interviewed for a job that you badly want and have just been asked that question. That's only the tip of what it's like trying to get your foot in the door at the 25 most difficult companies to interview with.

Each year, job information site Glassdoor runs an extensive analysis on users' ratings of their job interviews and picks the 25 companies known for the most difficult interviews.

The data came from 170,000 reviews of interviews that users had gone on. The site users rate the difficulty, whether the experience was positive or negative, how many days the process ran, and sample questions.

The question about a brick -- actually a common question to test someone's creativity -- was used at semiconductor company Nvidia, No. 20 on the list. That's right, it can get much tougher.

Glassdoor has compiled this list for the last three years and each time consulting firm McKinsey & Company was at the top, with an average difficulty rating of 3.9 out of 5. The full interview process takes about 39 days, with 77 percent of the interviewees reporting a positive experience and 12 percent, a negative one. The second and third toughest were Thoughtworks and Boston Consulting Group.

Out of the top 25, Paycom had the highest percentage of negative experiences, compared to the average of 13 percent, according to Glassdoor. The most popular companies, based on positive experiences, were Rolls-Royce and Avaya, which tied at 86 percent. The average of positive experiences was 52 percent.

Although the average interview process for all companies rated on Glassdoor was 16 days, some of the difficulty for the top 25 may be how long it takes to get through the process. The average for them was just over 31 days. The longest were at Teach for America (55 days), Procter & Gamble (50 days), and Rolls-Royce (46 days).

Here come the questions: A business analyst candidate interviewing at McKinsey got the question, "How would you calculate the annual carbon emissions from electric versus gas vehicles in the EU?" The easy answer would seem to be that electric vehicles don't emit carbon because they don't burn fuel or have exhaust. However, the electric power has to be generated somehow, and that will involve some amount of emissions. (Non-profit International Council on Clean Transportation wrote a 24-page paper trying to answer that question.)