ANN ARBOR, MI - 2016 was a remarkable year for the growing Ann Arbor-based Duo Security, a cyber-security company making plans to hire even more new employees.

Some of Duo's success last year includes an increase of 135 percent in recurring revenue growth, rising $42 million from 2015 to 2016, and the addition of 150 new employees, said Chief Operations Officer Zack Urlocker.

"One nice thing for Michigan and Ann Arbor is we are creating a ton of jobs here," Urlocker said. "This year, we're going to grow another 150. It's not just a great company for Michigan, it's a great company."

It is the fourth year in a row Duo has doubled its annual recurring revenue. 2016 also marks the first year Duo's financial information was made public and the first year the company attained positive cash-flow.

Dug Song is co-founder and chief executive officer of Duo Security and said 2016 was one of "exceptionally strong growth" for the company.

"With our focus on innovating - as seen by today's launch of Duo Beyond, the first commercial implementation of Google's BeyondCorp architecture - we are confident that Duo will continue to deliver exceptional offerings for our customers and deliver strong results," Song said in a company statement.

Urlocker described Duo as a company that has come a long way in just a few years and has much more in store.

"Now we're protecting some pretty important organizations and I think that's also given us a bigger role in the industry," Urlocker said. "We have a bigger voice in the industry, and also a bigger responsibility."

That responsibility has meant adding more employees to handle a growing number of customers and product offerings. Duo now employs around 380 people across multiple locations, including a new location in Austin, Texas, and services around 8,000 customers across more than 100 countries.

Some of those companies are common household names: Facebook, Etsy, Threadless, Yelp, Kayak, NASA, Sony and the University of Michigan, organizations looking for a different approach to security that Duo provides.

"Security has always been important but a lot of the older security companies were focused on having a hard perimeter around a business to secure the network," Urlocker said. "That old approach just doesn't work."

That's where Duo comes in, he added, as a smaller company with innovative ideas that are necessary to compete. Ideas like those introduced in 2016, including Duo's own secure single sign-on technology and the Insight phishing simulation tool that allows companies to test their abilities.

Duo's newest product is Duo Beyond, in what a company statement calls "the first major commercial implementation of Google's BeyondCorp framework that drastically improves and simplifies the security management of how employees and devices access critical corporate applications."

"It creates an environment where employees can access all cloud applications they need, using whatever mobile devices they need, and you know they are secure," Urlocker said about Duo Beyond.

Duo now has a name for itself in the software-as-a-service (SaaS) industry, thanks in part to the company's co-founders and their emphasis on cloud-based technology setting it apart from other similar companies.

"They made a lot of important bets... that have paid off," Urlocker said about co-founders Song and Jon Oberheide. "We're on the right side of history, in terms the world is moving more and more towards cloud and mobile devices and that's the kind of security we provide people."

Those bets have also resulted in a phenomenon Urlocker called the "Michigan boomerang effect," that has brought professionals back to Ann Arbor from metropolitan areas like New York City and San Francisco.

"It is a great community," Urlocker said. "There's a sentiment we have here, on really working together and collaborating. It's not a cut-throat environment like you might find in New York or San Francisco."

Though Duo's reputation and growth is enabling the company to expand, Urlocker said there are no plans to open other locations in 2017 but to simply focus company efforts.

"We're not really a start-up company anymore," Urlocker said. 'More people are recognizing the name. Duo has got a good reputation now."