Most companies start off steeped in culture. They begin as programmers pulling all-nighters writing code or scrappy advertising agencies teeming with wild ideas hashed out over informal brain-storming sessions.

But as companies grow, and specifically when they grow rapidly, structure sets in -- often at the culture's expense.  Soon a company that was founded on a wildly creative, loose and fun company culture runs the risk of becoming bureaucratic, stale and uninspired.

More and more companies are realizing that rapid growth when not paired with an equivalent emphasis on company culture, poses a threat to a company’s ability to recruit and retain employees, innovate, inspire creativity and build brand loyalty.

Feeling like your company may fall in the same trap? Check out our advice from two fast-growing companies and one corporate culture expert.

1. Ditch the hierarchy and focus on a flat company culture. Offerpop is a rapidly growing company in a fast-moving industry. Based in New York City and backed by venture investors, the social marketing software-as-a-service company has added more than 45 employees and opened offices in London and San Francisco in the last year. 

Related: Creating and Keeping a Positive Company Culture

But walk into their three-floor offices in Manhattan and you will see company CEO and founder Wendell Lansford sitting next to an Offerpop employee six months out of college. This flat company culture, room for career advancement and company sports teams are all key to Offerpop’s success in recruiting and retaining employees in a market that has them compete directly with high-paying industries like investment banking.

“The company is very flat in terms of the work chart,” says Kevin Bobowski, vice president of marketing for Offerpop. “Informally, it is an incredibly flat structure because anyone can come up and talk directly to the CEO, co-founders and executives.”

Besides having a flat culture, Offerpop builds on that camaraderie by fielding soccer and basketball teams, which allow employees to interact outside of the work environment. They hold trivia nights at the office, and when they launch a new product, they celebrate with a company-wide Poplaunch party where popcorn is served and different departments mix and mingle.

“It allows people to connect, which is harder as the company grows,” says Bobowski.

The emphasis on a vibrant workplace has paid off for Offerpop. Some of the company’s more successful new employees are often hired from referrals, as Offerpop builds a culture of “doers, not delegators,” says Bobowski.

2. Instill passion and personal values. Reno, Nev.-based digital agency Noble Studios has grown 40 percent in the last year, a year after being named one of fastest-growing companies in the nation. Much of the company’s rapid revenue growth came from an early company culture formed without a thought toward the bottom line.

Related: Making Gratitude Part of Your Company Culture

“We care about our clients -- money was the last thing that we actually thought about,” says Noble Studios founder Jarrod Lopiccolo. “We love creating and we love giving value.”

One way the company does this is through book clubs, where teams read and discuss the same text. Team leads pick the books with an eye for topics that specific teams needs to delve into. The book clubs help align teams, spur discussion and ingrain a culture of learning in the company.

The book clubs are one component of what Noble Studios has become known for in Reno -- building the talent and knowledge of a homegrown team in a second-tier technology city.

“A lot of the talent we had to grow,” says Lipoccolo. “But they had to have the right ingredients -- the ability to think long term and not short term. It’s exciting for companies to think that secondary markets can foster and maintain this level of talent.”

3. Remember the big picture. Odyssey Teams is a Chico, Calif.-based corporate training company that has worked with some of the globe’s largest enterprises to build and maintain culture.

Related: Google Employees Confess the Worst Things About Working at Google

One of the fundamental ideas behind Odyssey Teams success is that many employees have lost track of the “why” of their work. They feel lost in a sea of co-workers all dealing with one miniscule portion of a very large task and fall into the uninspired monotony and ritual of completing their work day after day.

Odyssey Teams breaks through that apathy by reconnecting their audiences with the reason they work, the difference they can make and the value of communication and collaboration in the workplace.

That says, Odyssey Teams co-founder Lain Hensley realizes that companies cannot always keep the same culture they had when they founded. They must be willing to evolve and adapt as they grow.

“You can't retain company culture when you are growing, you must carefully architect its evolution and surrender to the fact that it will never be the same as it was in the past,” says Hensley. “Look forward and build something new that would put any startup, like you used to be, out of business in a flash.”

Hensley says that good company culture does not always mean a conflict-free environment. But strong cultures can survive conflict, and even benefit from it.

“You need explosive ingredients to make a dynamite team, so be ready to work carefully and deal with a few explosions now and again. If that happens you are on the right track,” says Hensley.

Related: How to Protect Corporate Culture in a Telecommuting World