Sunay is the senior staff engineer for the Solaris Networking and Security Technology group. He has designed, developed, and led projects in the Sun Solaris kernel/network environment to provide new functionality, performance, and scalability.

He is the architect and tech lead for the redesign of the Solaris network stack, code named FireEngine. The new architecture allows the system to vertically partition the workload using an IP classifier-based, lock-less design. It reduces the overhead of synchronization and cross communication between CPUs, which can significantly increase performance and scalability.

Sunay was one of the key people behind Network Cache and Accelerator (NCA), which provides an alternate path from the sockets layer all the way down to the device driver. It also produced significant performance improvements for web-type workloads over the pre-FireEngine Solaris stack.

He was also responsible for the introduction of the Sendfilev system call and support in the Solaris 8 OS. He was part of the team that brought 64-bit networking to the Solaris 7 OS.

Before coming to Sun, Sunay was a researcher at the Indian Institute of Technology, Delhi for four years. During a two-year stint at Stanford, he was also involved with the Center of Design Research creating smart agents and was part of the Mosquito Net group experimenting with mobility in IP networks.