Great employees are important to any company's success, but especially critical at a start-up. In the tech sector, a great software developer will produce more than 10 mediocre ones--and likely avoid costly missteps in the process. At CarGurus, we've proven that theory beyond a doubt. We don't have an army of engineers, but we've still cracked the top ten in most trafficked U.S. automotive shopping sites and are ranked as the fastest growing site in the category here in the United States.

That kind of momentum is based on smart development and employees who "get it." Like most start-ups, we aren't in a position to take risks with employees who are underperformers or a poor cultural fit. In fact, we joke that we interview 15 candidates for every new hire, but it's not far from the truth.

As you keep a discerning eye on your talent pool, here are five keys to keep in mind:

1. Use your current employees.

Good talent knows good talent. One of our most productive recruiting tactics has been an employee referral program based on a cash bonus incentive for helping us hire candidates referred by our existing employees. This achieves a few important goals: it demonstrates our faith in current employees, gives our employees a chance to make a little extra cash, and allows us to hire candidates that have the ultimate references--our own employees.

2. Hire great athletes, not specialists.

Companies often put too much emphasis on finding employees with "relevant experience." Your top performers will end up being smart, resourceful, and innovative--three elements that have nothing to do with prior experience. When I helped co-found TripAdvisor, we avoided hiring employees rooted in the travel business. This tactic brought us people with no preconceived notions about the category, just good ideas and tons of smarts.

I compare this to the athletic arena. Great athletes can shift from position to position and make an impact using their skills. My hometown favorite New England Patriots are notorious for drafting the best athletes they can find, regardless of the player's prior experience in college or the pros. The Patriots have been known to take wide receivers and turn them into defensive backs. They simply want the best possible athletes on the field.

Your team members should be able to use whatever experience they have to rise to a new occasion--not recycle what they've done before.

3. Keep your standards high, even when the pressure is on.

Fast growth creates its own set of "happy problems," the biggest of which is staffing a company experiencing fast growth. This is a huge pitfall for start-ups, as they let the pressure of the moment outweigh the need for long-term stability.

Use your growth to attract good talent, but don't let the need for speed influence your decision on a hire. One bad apple in the environment will rot the whole team.

4. Make candidates pass the "drink a beer with me" test.

Employees have to be comfortable having a conversation with one another--and that includes the CEO. I make it a point to interview every employee we hire. Once the rest of the team has a positive reaction to a candidate, I'll sit down with the applicant for a final "fit" test. I'm not necessarily looking to probe their coding or marketing skills. Rather, I'm looking to see how this person will fit into our overall culture.

Usually, it comes down to a simple question on that front: would I want to grab a beer with this person? If I don't think we can be at ease in a semi-casual setting, I hesitate to add them to the cultural mix.

5. Sell them on your company, too.

It's easy to feel like you hold all the cards in the recruiting process, especially in a down economy. If they're good enough to impress you, though, they could likely nail down an opportunity elsewhere.  That's especially important at a tech company like CarGurus. There  is a lot of industry competition for top developer talent.

Make sure you respect their power as a strong talent, and sell them on the benefits, personality, and development opportunities within your company.  The worst that can happen is they want to join you even more.