A profile of hiring at Kayak, where Paul English works hard to bring in the best talent to compete in a very complex space.

English is like a baseball scout with an incredible network of tipsters, willing to fly anywhere at a moment’s notice to see a hot prospect. “The difference between an A player and an A-plus player,’’ he has said, “is the difference between a million in revenue and a billion in revenue.’’ And yet his approach to hiring is unorthodox in the extreme.

With more than 100 employees in Concord and Norwalk, Conn., Kayak does not have a human resources department. The “jobs’’ page on its website not only doesn’t list open positions, but it doesn’t include an e-mail address, fax number, or mailing address where one might send a resume.

English also prods Kayak to adhere to the “seven-day rule,’’ which he devised while helping run a local office of software company Intuit Inc. When he first hears the name of a superstar working anywhere in the world — whether a designer, programmer, or software tester — he gives himself seven days to find the person, conduct interviews, make an offer (assuming the prospect lives up to advance billing), and get an acceptance.

He also gives a memorable thought on what makes an outstanding candidate:

English has developed some of his own terminology to talk about good and bad candidates. Good ones are “energy amplifiers’’; they increase the energy of everyone around them. Bad ones are too arrogant about their abilities or too humble; the right people display what English dubs arrogant humility. “It means being confident in what you’re good at,’’ he explains, “but humility to me means being curious.’’