Mike Cahill, former Boku vice president of engineering and one of the company's earliest employees, has accepted the position of CTO, returning to Boku after a two years serving as vice president of mobile engineering at American Express. Cahill was with Boku for nearly four years, from the company's founding in early 2009 to late 2012.

"There's a great sense of momentum and strength for Boku that has been amazing to see from afar, and that played a very large role in my decision to return," said new Boku CTO Mike Cahill. "As CTO, I'm looking forward to tackling the tremendous opportunities that are in front of Boku as the firmly established leader in carrier billing following their mopay acquisition. Even more interesting are the technical innovations and challenges ahead, as we bring carrier billing into more new venues and real-world verticals. In short, it's very good to be back."

As CTO, Cahill will be responsible for leading Boku's global engineering and technical operations. He will operate out of Boku's San Francisco headquarters, lead technical teams in the U.S., U.K., Germany, and Romania and provide technical guidance to Boku employees across the globe.

"I know the team at American Express is as sorry to see Mike leave as we are happy to have him return," Said Jon Prideaux, Boku CEO. "Mike contributed so much to Boku during four of our company's most critical years. When the opportunity arose for him to join an established player on the carded side of our payments universe, I knew from my time at Visa that he would be gaining invaluable experience. To be in a position to bring him back as CTO, benefitting from those two years of experience combined with four years spent building Boku – we simply could not pass that up."

While at American Express, Mike was responsible for the company's app development and company-wide mobile application and mobile payment frameworks. His achievements over the course of two years include projects ranging from the implementation of Apple Pay to the development of several American Express applications. He also managed both national and international engineering teams in New York, Phoenix, Palo Alto and London.