Anybody that's ever worked at a tech start-up can tell you it's a work experience unlike any other. It is fast paced and unpredictable. Your job description is apt to change with some frequency. Great ideas live in scribbles on white boards, not in power point decks. Meetings happen around a monitor, not in a board room.

In my experience building two web companies, TripAdvisor and now CarGurus, I've had the chance to work with some incredibly smart, talented employees. The best of them share some common traits that I have come to view as the "indicators" for success at a start-up.

1. 80/20 Vision

I've talked about the 80/20 rule before, and it's just as critical for employees at a start-up as it is for the CEO. There are hundreds of things you could focus on at any given time, but only a few of them will really make a difference to the product and the company. Basically, 20 percent of your work input accounts for 80 percent of your results. The individuals that have the ability to prioritize according to this rule will help the organization work faster and smarter.

2. Thick Skin

In a start-up environment, there's not a lot of time for politeness or diplomacy. The best employees are the ones that brazenly fight for a good idea and boldly say no to a low priority request. They don't worry very much about perceived impertinence or hurting anybody's feelings, nor do they take anything too personally. The ability to dish it out and take it is critical at a start-up.

That goes all the way to the top. At TripAdvisor, there were plenty of times that my partner Steve Kaufer and I disagreed. If we took any of this conflict personally, we couldn't have gone very far. At my current company,, our most successful people are the ones that are pushy about getting their jobs done and done well. While they can co-exist with others on the team, they are not shy and don't worry about hurting other's feelings. Start-ups are not popularity contests but rather are about generating results.

3. Resilience

The best tech start-up employees don't let failure get them down. Whether it's broken code, a failed A/B test, or something much, much bigger, they have the ability to pick up and move on quickly, usually with some humor. Yes, they learn from their mistakes, but they don't expend too much time or energy reflecting back. Instead, they are already looking forward.

At CarGurus, our employees operate with the assumption that we will most certainly fail along the way to making better products or a better consumer experience--that's the job. The greater failure is not moving fast enough to keep testing new ideas.

4. Ownership

At many start-ups (especially technology companies), early employees typically have some kind of an ownership stake in the form of stock options. But the kind of ownership I am talking about is actually more of an attitude. Those that fully embrace the company vision. They care about how the company's product affects its customers; they want to know what customers think. These employees are ever curious about the industry, and they are always thinking, often waking up in the middle of the night with an idea or sending an email to a colleague on a Saturday. Without that sense of ownership, it's just a job that ends when the clock strikes 5 p.m. Like an owner, successful start-up employees think about their "job" seven days a week, 24 hours a day.

5. Sense of Humor

Put a lot of people in (typically) small digs and add some stress and there's potential for a disaster. I've talked before about the importance of company culture in the life of a start-up. Most of the best employees I've worked with bring to work a great sense of humor, and whether they realize it or not, that helps to form a great company culture. They know how to defuse tense situations, they find fun in the big challenges, and ultimately they help to make the company a place that people want to work.