Sonu has extensive experience in the Instant Messaging space. Sonu was the co-founder and COO of Flash Communications, where he architected and patented the first federated Instant Messaging server platform in existence (he has 6 other IM patent applications to his credit). Flash was acquired by Microsoft in 1998 to form the basis of the Exchange Instant Messaging product. As Lead Program Manager for Exchange Instant Messaging, Sonu led the Exchange Instant Messaging team. He was instrumental in developing the Microsoft vision for enterprise Instant Messaging, and the design and architecture of Exchange Instant Messaging.

He was also instrumental in developing the RVP Protocol used for Exchange IM. Sonu represented Microsoft in the IETF (Internet Engineering Task Force) effort on IM standardization, where he was a co-author of Internet RFC 2779, "Instant Messaging Presence/Protocol Requirements".

Sonu has a B.S. and M.S. in Computer Science from the Massachusetts Institute of Technology, where his research work produced the first Time-Optimal Self Stabilizing Spanning Tree Algorithms for distributed computer networks.