Sep 2015 – Nov 2017 · 2 yrs 2 mos · Bengaluru Area, India

• At Snapdeal we successfully created one of the largest Openstack based private cloud (100,000+ cores, 4PB SDS) using 100% Open Source technologies - with Openstack, Qemu, KVM (Linux Kernel), Ceph (Storage) being at the heart of it.
• I was the Technical Architect for the whole project and as the Architect I'm proud that we took many right decisions which helped us move Dev-n-Test fully to our private cloud in a short span of 3 months, and then in another 3 months the Production cloud was ready. Currently the snapdeal.com production has been fully migrated to our private cloud which was designed with two basic mantras - Robustness and Performance.
• http://engineering.snapdeal.com/snapdeal-launches-its-own-cloud-snapdeal-cirrus-201609/
• http://engineering.snapdeal.com/hybrid-cloud-a-path-between-the-seas-201609/

Sep 2008 – Sep 2015 · 7 yrs · Bengaluru Area, India

• As one of the senior most Technical R&D members of the team, I was responsible for kick-starting lots of projects in VMware India. Along with leading various projects, I mentored junior team members and helped them grow. Some of the key projects that I was part of.
• > VMWare Virtual Volumes (VVol)
• http://www.vmware.com/in/products/vsphere/virtual-volumes.html
• VMWare Virtual Volumes technology allows storage array vendors to extend their value added services to VMs. f.e. VVol enables compliant storage arrays to perform various storage operations like snapshot, clone, replication, etc at VM granularity.
• I was the Architect for the VVol project and here are some of the note-worthy achievements.
• Clearly defined the VVol API spec enabling consistent implementations from various storage partners with very few iterations.
• Robust and performant VVol implementation for ESX, that storage partners could test against.
• Helped storage partners extend VVol support to their arrays.
• Numerous scale challenges.
• > VMWare SVA (Storage Virtual Appliance)
• http://www.vmware.com/in/products/vsphere-storage-appliance.html
• SVA runs as a Linux virtual appliance that uses Linux MD-Raid1 for replicating across the network.
• Lot of performance optimizations, including a novel read balancing algorithm that exploited disk layout to get 10-15% better random IOs/sec.
• > Worked on various layers of ESX storage stack.

Nov 2002 – Sep 2008 · 5 yrs 10 mos · Bengaluru Area, India

• TCP offload engines (TOE) were becoming a craze those days. I was fortunate to be involved in one of the first TOE implementations (http://download.adaptec.com/pdfs/installation_guides/ana7711_v10_gs.pdf). This was implemented completely as a Linux kernel module which could add TOE support to a stock Linux kernel by live patching of kernel socket hooks.
• Later, perceived, designed and implemented a generic TCP offload framework for Linux (2.4 and 2.6) with the intent of proposing to the Linux community for inclusion in Linux.
• Various other interesting projects:
• Porting Linux to custom ARM and PowerPC boards
• Added zero copy networking receive support to get reasonable performance on these relatively "weak" CPUs
• Misc performance optimizations like use of sendfile(), epoll(), batching SCSI commands, cache profiling, etc
• iSCSI initiator
• A Storage Virtual Appliance using Linux DM (device mapper)

Apr 2000 – Nov 2002 · 2 yrs 7 mos · Bengaluru Area, India

• Worked on various modules of a Terabit Aggregation Router - IPC (Inter Processor Communication) for a Ethernet based fabric, IP forwarding plane, various SNMP MIBs, and other misc stuff.
• Created one of the first working MPLS (Multi Protocol Label Switching) stack while it was still in IETF draft stage. The forwarding plane was implemented in Linux kernel 2.4.

Feb 1999 – Apr 2000 · 1 yr 2 mos · Bengaluru Area, India

• Developed a software solution for optimal placement of components in a chip, resulting in increased die efficiency.
• This solution was used by TI's internal Chip Placement and Routing team and it increased the automatic coverage from ~30-40% to ~75-85%. It replaced a commercial EDA tool that the team was previously using.
• All in all a sweet success and a huge moral booster!

Sep 1996 – Jun 1997 · 9 mos · Bengaluru Area, India

• Still an electronics enthusiast at heart who used to hate computers in school, this was my first job where I was introduced to the beautiful world of computers!
• Mainly worked on ABB's industrial automation cards. I would say 80% h/w 20% s/w.
• Most interesting and memorable part was solving a long pending problem in one of the CPU cards which was causing the bootup to fail. There were ~50 CPUs cards worth tens of crores lying around in the inventory, rendered unusable because of this bug. It was a multi-layer PCB with close to 300 major components.