

Balachandar Karthikeyan is the only Indian to have contributed to both WhatsApp and Signal, the two biggest messaging platforms in the world. Balachandar and the founders of these messaging apps have a close working relationship. A self-taught techie, he learned all skills through books and Internet.
For the opportunity to collaborate directly with WhatsApp, Balachandar did not go through a typical interview process. After dropping out of college in 2015, he found the WhatsApp security flaw and reported it to the concerned team, which caught the attention of the company’s co-founder, Brian Acton, who later gave Balachandar a chance to contribute to WhatsApp.
Balachandar was the only person in India working for WhatsApp at the time. His ideas contributed to the success of many important WhatsApp features, including Status, Groups, Video Calls, Payments etc. He was also responsible for ensuring that the final product was high quality.
After five years with WhatsApp, Acton quit to start his next venture – Signal. Balachandar too followed him.
When WhatsApp changed its privacy rules a year ago, Signal became very popular. In an interview, Acton talked about Balachandar's work with international media. “I have a colleague in India. He gives me product ideas. I think that's the best way to build a product for India.”