In 2010, Tiago Paiva had just graduated from Instituto Superior Técnico in Portugal with a master's degree in computer science, and was working for Procter & Gamble. But instead of continuing to work a well-paying job at an established company, Paiva, along with his former classmate Cristina Fonseca, decided they wanted to build a business of their own.

Paiva and Fonseca, both 24 years old at the time, developed a few websites and started making some money on ads. In 2011, they came across a contest hosted by Twilio, a voice messaging and text platform used in apps like Uber and Airbnb, to build a startup based on Twilio's programming interface. The winner would receive a MacBook Air. "I was pretty broke, living with my parents, and we decided to give it a shot," Paiva says. "In 10 days, we built Talkdesk."

The startup the duo feverishly developed is a cloud-based software-as-a-service platform that enables businesses to create a virtual call center in just a few minutes. For most small businesses, Paiva says, a lack of account and personal information causes significant problems on customer service calls. Representatives have to ask each customer for their name, account number, social security number, and phone number. But with Talkdesk, when someone calls, the software provides all the customers' information from your database, as well as all publicly available information online, in real time.

"This way, the customer service agent sees the caller's name, e-mail, account number, Facebook and LinkedIn profile, all the previous customer interactions with that customer, what they previously bought from your company, and more, all in one place," Paiva says.

After submitting their work for the contest, Paiva and Fonseca were notified that Talkdesk was a finalist for the Twilio contest and that they needed to be in San Francisco in two days to present the demo. "I had never been to America before. I had to rush to get my passport on Monday, and flew out on Tuesday," Paiva says.

The Talkdesk founders won the contest and while there met one of the judges, investor Paul Singh, who at the time was a partner at the accelerator 500 Startups. Singh persuaded them to join and staked them with $50,000 to further develop the company. Paiva stayed in the U.S. to continue to make connections while Fonseca returned to Portugal. At 500 Startups, the duo worked remotely to improve their call center platform and hired four new employees.

Paiva says that moving to the States had its difficulties. "Everything is so expensive in the U.S., so before we got the money from 500 Startups it was complicated. I only had $1,500 on a credit card and I remember sleeping on the floor at 500 Startups and eating the food they had there," he says. It also took him six months to get a working visa after his initial application was rejected.

After demo day for 500 Startups, Talkdesk received $350,000 from an angel investor, which provided visibility and led to new customers. Even after the infusion of capital, though, Paiva worked alone in the U.S. at a small space in Mountain View while the rest of the team was in Lisbon. "It helped us early on to have our employees in Portugal. Talent is much cheaper over there, which allowed us to save money and perfect our product until we had a stable number of customers paying us," he says.

After landing customers like Chevrolet and Coca-Cola, Talkdesk is generating a couple million dollars a year in revenue. The startup continued to stay lean until two months ago, when the team leased a bigger office space in Mountain View and hired 15 U.S. employees. Each month, Talkdesk hires five more employees. Through all the twists, turns, and rapid development, however, the company just keeps iterating its core product, Paiva says. "During those 10 days, we only built a proof of concept, but it's still what Talkdesk is today."