Plivo, a “telephony as a service” startup that took the stage at Y Combinator Demo Day today, is taking on Twilio, a popular pay-as-you-go API provider for the cloud.

For founders Venky Balasubramanian and Michael Ricordeau, Twilio has weaknesses that they can exploit. “Their company is built on Asterisk and doesn’t scale,” said Balasubramanian. Addressing a packed house of investors, they said that their first five customers switched from Twilio for this specific reason.

The Walnut Calif.-based company was founded in 2010 when Michael and Venky accidentally exchanged messages over Github while trying to integrate telephony into their web applications. On the company website, they wrote that they realized that telephony application development “took a painstakingly long time.”

Plivo is one of the companies in the current pack of Y Combinator startups. It is one to watch as the company is already pulling in significant revenue. The founders revealed that they already made $52,000 in revenue this month and have supported 25 million voice minutes on their platform.

The audio problem: Learn how new cloud-based API solutions are solving imperfect, frustrating audio in video conferences. Access here