Goldman Sachs’ interviewer stumps both himself and his intellectually insecure interviewee with a question on the cohomology of knots

Despite the fact that Google has statistical proof that the marginal return from additional interviews diminishes to almost nothing after four (interviews), Goldman Sachs remains notorious for the rigorousness of its interview process. Ten interviews are standard. Twenty are within the realms of normality.

Not that this seems to put people off. In November, Lloyd Blankfein proudly claimed that 90 percent of people offered a job with Goldman Sachs accepted last year, even though most of them had multiple offers from rival firms.

However, Goldman’s newly-developed careers blogs suggest that some of its interviews can be trying.

Most notably, Richard, a vice president in the bank’s investment banking strategy group (who says he reads math books like most people read fiction and suffers from intellectual insecurity), says he was asked a question of such complexity that the interviewer stumped himself and took half an hour to work it out, while Richard sat in silence.

The question was related to the mathematics of knots, the subject of Richard’s senior year thesis. “It was a topic I knew – and still know – nothing about,” says Richard. Nevertheless, he got the job.

Richard also describes Goldman’s mercurial methods of encouraging staff to stay.

Toward the end of his time as an analyst, he says he had a “quarter life crisis,” having assumed that his “opportunity set at the firm was empty.” Thereupon, he went to see Paul, his Goldman mentor, who said:

“You can leave if you want. But, before you do, you need to come into my office and convince me that you’re excited about what you’re leaving for. If you can do that, great, and stay in touch. If not, you’re making a huge mistake.”

Richard was promptly persuaded to stay and says staying was “one of the best decisions of my life.”