Tim Liu has been cradling the phone to his ear for more than an hour as he rapidly types on the computer keyboard. The call from Sanjay Patel had come out of the blue. Patel was struggling with a mobile app proposal; he just couldn't quite get the proposal to match the concepts in his head. He thought of Liu.

The two Carnegie Mellon alumni were introduced in 2006 when Patel was president of the association's Boston chapter. Liu, who was the former president of the Washington, D.C. chapter, offered insights to his younger acquaintance. Although there was an age difference of 15 years—Liu earned his degree from the College of Humanities and Social Sciences in 1985 and Patel in 2000—they kept in touch and became good friends.

Liu learned all about Patel's "interesting" career path. Patel believes he got his lucky break when he got laid off from his first job at Laboratory Technologies, just a year after he graduated. It made him start his own business. After a year of start-up work, Perpetuating Technologies, a Boston-based software development company, emerged. His first major client was Dunkin' Donuts. More followed. Liu's professional background was far different. He had plenty of corporate experience, 25 years in all, including 13 years at PricewaterhouseCoopers, the global professional services firm.

Now, Patel is relying on Liu's experience to help him solve his proposal dilemma. "I just felt the urge to call Tim," Patel says. "While we were on the phone talking through the proposal, Tim created this dynamic visual concept that captured exactly what the client wanted. We had amazing synergy together."

That synergy makes Patel wonder whether they could work together on a permanent basis. Liu, who now lives in Chicago, isn't so sure. Liu describes himself as a hands-on learner who wants to solve problems rather than simply discuss them. Patel responds that he likes to focus on possibilities and look to the future rather than the past. Sounds very complementary, but, just in case, Liu wants to know Patel's personality type, according to Myers-Briggs, the popular psychological test that reveals how people perceive the world and make decisions. Liu already knows his personality type is Extraverted Sensing Thinking Perception (ESTP). In plain English, that means he is action oriented, logical, resourceful, outgoing, charming. He discovers that Patel is Introversion, iNtuition, Thinking, Judgment (INTJ), which characterizes him as analytical, pragmatic, logical, creative, independent. A match!

They began working together last year as part of Patel's company, Perpetuating Technologies. They create mobile applications, with Patel serving as an advisor on their digital online and mobile strategies and Liu developing mobile strategies and managing iPhone application development projects. In addition to Dunkin' Donuts, the firm's client list includes such well-known businesses as Horizon Blue Cross and Thomson Reuters.

Patel feels that he and Liu were meant to work together: "Tim and I really challenge each other. Together, we are able to come up with things that separately we would not be able to create. I think that's really the key thing. We have such a distinguished and different background and approach—and it creates a deep, amazing, and creative output."

An ideal example of their collaboration's output is their work with client CourseSmart. "CourseSmart lets students access their textbooks on the iPhone/iPod touch or Android phone in addition to their laptop/desktop," explains Liu. "And they pay up to 50 percent less than printed textbooks. So the times they are on the go, not lugging their textbooks or laptops, they can study anywhere."

The app has received national media coverage, including from The Wall Street Journal, The New York Times, and The Washington Post, along with respected tech Web sites, such as CNET, Lifehacker, and Engadget. The work on the product design and development has led to a patent application.

Some other innovative phone apps that they have honed are Practice Rx, which provides doctors with real-time critical alerts, and CLE Mobile, used by attorneys to enhance their knowledge through mobile education. The effectiveness and popularity of their apps have caught the attention of Apple, which ranks Perpetuating Technologies as one of its top iPhone app vendors.

"Really, we just ask our clients a lot of questions," Patel says modestly when discussing the company's impressive recognition. "Our clients are the experts in their business. We ask the questions and find out the who, what, when, where, and why and then add technology."

Liu agrees that the secret to their success is more than hard work. "In order for us to come up with the best possible solutions, we have to become part of their business. We know the clients have the content, but they need help to create great user experiences so the focus is on the user and client goals, not just technology."

The two—who serve on the university's alumni association board—clearly appreciate their partnership, which began simply because they had the same alma mater. "I wish I would have been able to start working with Patel years ago," says Liu.

So does Patel. He says the two have made a commitment that no matter what future endeavors they do, be it a spin-off company or a new business, they want to work together because "it just makes sense."

Laurel Furlow, a former newspaper reporter, is the assistant director of on-campus programs in the Office of Alumni Relations.