Sef Kloninger   @sefk

Hands-on full-stack engineering leader who loves the Internet. My roots are in backend/ops but lately I've been more interested in frontend and open-source. I've built and scaled distributed systems; now I'm happy to buy when I can. For fun I code in JavaScript and Python. I've led teams of 100+ engineers at Akamai and VMware, and small teams at Ning and Stanford. I built and launched an open-source MOOC platform in eleven weeks. Had a blog post hit the Hacker News top spot. BS Computer Science, Stanford 1993.

YouTube / Google San Bruno, CA
Tech Lead Manager, Data Infrastructure (9/2015-present)
Build and operate infrastructure for YouTube's core data warehouse. Support the analysis of usage data from over a billion active users.

Wavefront Palo Alto, CA
VP Engineering (9/2014-3/2015)
Led six engineers building pre-launch service for monitoring infrastructure at scale. Developed backend features in Java and frontend features in JavaScript (Bootstrap, FlightJS, Require). Operated sizable Amazon Web Services deployment with Chef: cleaned up security groups and IAM roles. Cut COGS by 50%.

Stanford Online Palo Alto, CA
Head of Engineering, Open Source Platform (6/2012-8/2014)
Engineering manager and core developer on Open edX, Stanford's open-source platform for Massive Open On-Line Courses (MOOC's). Negotiated merger with edX; worked with them to open-source their code and move to an open development process. As the strongest technical voice in Stanford Online Education, defined our multi-platform strategy with senior leaders and trustees. Reported to the Vice Provost for Online Learning.

Over Summer 2012 built and launched Class2Go, the first open-source MOOC platform. Ran successfully for 200,000 students until merged with edX in April 2013.

  • Engineering Manager: Line managed small engineering team. Ran agile process with weekly sprints and demos; established code review and releases. Hired three engineers and many students. Set up GitHub, GitHub Issues, Huboard and Google Docs. Established just enough process.
  • Dev/Ops and Release: architect of the run-time system built on AWS (EC2, S3, RDS, SES), ansible/chef, and celery/SQS. Lived and breathed git. Coordinated all releases. Managed capacity, fixed production issues.
  • Core Engineer: core app features: queueing, oAuth integration, and operations tools.

Ning Palo Alto, CA
VP Infrastructure Engineering and Operations (12/2010-4/2012)
Operations. Oversaw the team running a medium-sized platform: 100K sites, 300M requests/day, 60M uniques/month, 240TB of user-generated content. Maintained four nines of availability. Established set of core technical metrics: incidents, availability, and performance. Built a mini-NOC. Defeneded againt DDoS attacks by choosing protection service provider after build vs. buy analysis.

Infrastructure. Line managed senior engineers on the core Ning platform: relational and key/value content, blob storage, messaging, service discovery, mail, activity, and API's. ~50 RESTful Java services. Ran project to convert Oracle to sharded MySQL. Improved performance by restructuring JS and CSS and targeted rewrites. Responsible for development and support of the Ning API.

Left shortly after the acquisition by Glam Media in December 2011.

VMware Palo Alto, CA
Senior Director, Desktop Virtualization Engineering (5/2008-12/2010)
Delivered server and client virtualization enterprise software to improve how corporate Windows desktops are deployed and managed. Hired to line-manage a small engineering team, grew to leading engineering for the Desktop Business Unit with 140 engineers in the US, UK, India, and China. Managed managers, directors, and three principal engineers (VMware's most senior technical role).

Delivered major releases that grew Desktop from $10M to $100M. Owned engineering for enterprise products, VMware View remote virtual desktops and ThinApp Windows appplication virtualization; personal virtualization with Workstation (Windows and Linux) and Fusion (Mac). Technical sponsor of two strategic transactions: acquisition of RTO Software for profile virtualization and OEM of Teradici's PCoIP remote display protocol.

Akamai Technologies San Mateo, CA (2007-08)
Senior Director, Service Performance (2005-08) Cambridge, MA (1999-07)
Founded the Service Performance group in Networks & Operations for advanced ops and high-touch customer engagements. Grew organization from six to 35 engineers and architects in US and India.

Improve service reliability by driving bulletproofing and scaling initiatives. Managed Akamai's incident response process. Define and measure core platform quality metrics, presented quarterly to CEO and Chief Scientist. Owned high-touch customer escalations and events, including: 2006 Olympics, March Madness, Microsoft patch Tuesdays, Hulu's launch, and Apple iPhone launch. Designed a unique cache hierarchy setup for long-tail social networking content.

Director and Senior Director, Engineering (1999-05)
Engineering Manager of 20-50 engineers and managers. Led technical hiring during company growth, then managed transitions and motivated teams during staff reductions. Mentor to other managers, senior engineers, and architects. Established processes for development, QA, and release engineering. Oversaw technical integration of two acquired companies.

Hands-on technical leader of Akamai's core technology. Handled many urgent service incidents; one of five crisis managers called in for the big problems.

  • Communication infra.
  • Security systems
  • HTTP and DNS
  • Load balancing
  • Coherence protocols
  • Fault tolerance
  • Linux kernel
  • Operations tools
  • Performance
Senior Software Engineer (1999)
Lead engineer on HTTP content server. Scaled technology and features for rapid pre-IPO growth.

FarSight Financial Services Cambridge, MA (1998-99)
Senior Performance Engineer
Enhanced performance of a website for retail on-line stock trading. Profiled systems, rewrote critical code paths (C++), and optimized database queries and schemas (Sybase).
Venturcom Cambridge, MA (1996-98)
Principal Software Engineer
Principal architect, engineer, and team lead of Component Integrator, a tool for customizing and embedding Windows NT and CE. Product bought by Microsoft, later released as the Windows Embedded Studio. Venturcom eventually became Ardence, acquired by Citrix.
McKinsey & Company, IT Cambridge, MA (1993-96)
Principal Software Engineer
Led development of client/server human resource system for internal use. Enhanced and optimized custom database replication system (Oracle). Attended week-long training sessions on communication skills, writing, and problem solving.
Veritas Software Santa Clara, CA (1990-93)
Software Engineer (Part-Time)
Developed and tested Visual Administrator tool suite (C, Motif, Xt).


  • Content Delivery Network (CDN) Content Server Request Mechanism With Metadata Framework Support (US 7,240,100 and US 8,122,102)
  • Internet content delivery service with third party cache interface support (US 7,010,578)
  • Method and System For Providing Content Providers With Information About How Their Users Access the Internet (WO 2002/017139)
  • Enterprise Content Delivery Network Having a Central Controller For Coordinating a Set Of Content Servers (pending, US 2004/0073596)

Education Stanford University, B.S. Computer Science, 1993
Research: "Verification of SCI Cache Coherence Protocol" under Prof. David Dill.

July 2016