Oct 2020 – Mar 2026 · 5 yrs 5 mos

Aug 2015 – Oct 2020 · 5 yrs 2 mos

Jan 2012 – Sep 2015 · 3 yrs 8 mos · Redmond, WA

• Worked on Meeting room devices for Skype. Developed Cordova based windows phone/Android/iOS companion apps for the device and worked on the device software on collaboration features like screen sharing.
• Worked on cloud based desktop and application streaming technologies, dealing with low latency protocols and signaling to establish remote sessions on commodity cloud hardware. Worked on machine provisioning and streaming protocols.
• Lead a dev team in building Bing ads advertiser tools. This team was responsible for delivering ingestion experiences for ad inventory and ad performance analytics.
• Worked on the Windows Notification Service. Designed and implemented the back-end of the notification service to handle hundreds of millions of devices and a very high notification throughput. Designed the backend and protocols of the service and several helper services that make the notification pattern simpler for app developers.

May 2006 – Jan 2011 · 4 yrs 8 mos

• Worked on Skype messaging service developing the server side infrastructure that supports Instant Messaging and activity streams for 300MM users with 40MM active sockets. Evangelized technologies and patterns to scale the service, developed tools to troubleshoot distributed systems and prototyped and enabled innovative customer scenarios.
• Prototyped, evangelized and implemented a large scale XMPP gateway for Messenger-Facebook Interop supporting 250k sockets per machine. Developed a .NET XMPP library that is used across groups.
• Designed and implemented geo-hosting for messenger server state where load is distributed across several data centers across the globe supporting users in different data centers to get presence and messaging for buddies who are logged into other data centers. Implemented a generic server to server protocol router for efficient routing between data centers.
• Developed a framework for middle tier distributed cache to be resilient against machine crashes and service rolls to maximize availability during failures and maintenance.
• Designed and implemented a load balancing service that gathers machine health from thousands of machines in a distributed hash table and provides this to thousands of client machines to facilitate stable hashing through deployments and machine addition/removal.
• Optimized server to server communication libraries to double performance and throughput. Implemented several optimizations like lock free queues, tries for domain lookups, state partitioning etc. to improve performance of the DHT that backs messenger state.

Jan 2005 – May 2006 · 1 yr 4 mos

• Software engineer and lead on several micro-projects in developing the next generation Global Perpetual Inventory subsystem at Amazon.com. This is a low-latency, high performance cache that handles requests for inventory availability from the amazon website and fulfillment systems. This system receives real-time updates from amazon warehouses when inventory position changes and summarizes this information to publish to the website.
• Developed tools to monitor the amazon availability pipeline
• Doubled the caching capacity of the system by fine tuning shared memory layout.
• Developed a set web services that roll-up availability data for items.

Apr 2002 – Jan 2005 · 2 yrs 9 mos

• Team lead for the development of Generic Workflow Framework for the server side development of a inventory/provisioning system. Proposed a XML based generic design approach and worked with the team to design/implement the framework. The Generic Workflow Framework is used to implement the server back-end functionality in terms of XML files. The framework interprets the XML and executes the workflow.
• Team lead for the development of Generic GUI framework for a telecom inventory and provisioning system. This involved the development of an XML based language that defines look and feel and the logic of different screens, and the development of servers to convert the backend data into XML. The XML is then transformed to XHTML using generic XSLT scripts. Design and development of the XML framework and the C++ server.

Nov 1998 – Apr 2002 · 3 yrs 5 mos

• Lead a team in designing and implementing a network performance management server that receives RADIUS data from network components calculates statistics and trends by evaluating expressions on several network variables in the packets. Since the server had high performance requirements, this involved the implementation of efficient queues and non-locking synchronization as well as measurement/optimization of code. The engine is
• designed to be data-driven in order to be extensible.
• Designed and implemented a high-performance, real-time messaging system for a server framework that needs to handle several thousand packets of data per second. This re-usable class library provides a publisher/subscriber interface to the user, shielding the user from low-level details like connection management, packet-filtering, re-binding etc. It encapsulates the CORBA interface and provides an easy to use C++ interface.

Jan 1996 – Jan 1997 · 1 yr