In the latest interview on Mixergy, Concur president Rajeev Singh explains how the Redmond maker of travel and entertainment expense management software transitioned from a germ of an idea in 1993 to a $3 billion company today. I’ve become a big fan of Andrew Warner’s interviews on Mixergy, and love when he features Seattle entrepreneurs.

“The story of the company is a set of inflection points where we had to decide what the customer would want and how they were going to want it, and then make big bets in order to get it,” said Singh, who started the company with his brother Steve, who is seven years older.

Rajeev Singh also talks about how his engineering father — who came to the U.S. in the early 1960s from India — inspired him as an entrepreneur. It is a really fascinating part of the discussion (about 10 minutes in), with Singh later talking about how he was miserable working at Ford Motor Co. in his early twenties.

“I decided, I can’t do this,” said Singh, who started studying to become a lawyer before joining with his brother on what became Concur.

Despite its success, Concur is a little bit of a hidden success story in the region. And how did the company do it?

Singh says it comes down to one word: hustle.

“We banged on doors until people didn’t want to talk to us anymore,” said Singh. “..More than anything, and this is true no matter what stage of the business we were in, if there is anything that is one of the hallmarks of the company, it is hustle. We don’t get outworked when we are after something like this.”

Full video here.