Sean Jain Ellis

Software Development and Life Adventures

Sean Jain Ellis

Engineering Leadership | SRE | Development | Infrastructure

Summary

Thirty years of experience architecting resilient systems, scaling and optimizing infrastructure and leading engineering teams. Proven track record of reducing operational costs, modernizing platforms and driving critical software transformations. Equally effective as an engineering individual contributor and leader.

Experience

Upstart

2023-2025
Principal Site Reliability Engineer
  • Reduced time-to-detect by 25% by automating golden-signals alerting based on historical trends.
  • Founded a postmortem bar raisers guild to perform retrospectives and enforce accountability.
  • Standardized MADR and Conventional Commits to enhance change documentation.
  • Standardized weekly operations reporting by developing Go and Python libraries and GitHub Actions that summarized incidents and presented performance metrics.

Twitter

2018-2023
Staff Site Reliability Engineer / Storage Tech Lead 2020-2023
Engineering Manager / Real-Time Storage SRE Teams 2018-2020
  • Led a system-resource-management initiative with $200M+ in projected five-year CapEx savings.
  • Unified C and C++ caching products into a single Rust service with integrated SRE tooling.
  • Drove hardware homogenization that avoided system procurement during 15% data growth.
  • Directed a Python 3 migration ahead of Python 2 end-of-life and moved 300 MB of legacy code into a monorepo.
  • Achieved 85% at-rest and 100% in-transit encryption adoption, including a 25% mTLS implementation.
  • Managed multiple distributed and remote SRE teams and migrated platforms from Mesos to Kubernetes.

Box

2017-2018
Staff Site Reliability Engineer / Edge Performance
  • Designed Voltron, a distributed firewall for Linux hosts, Kubernetes, OpenStack and network equipment.
  • Migrated edge proxies from Apache Traffic Server and HAProxy to NGINX, using ExaBGP and anycast for service discovery, traffic steering and resiliency.

DreamWorks Animation

2007-2017
Engineering Manager / Nova Rendering SaaS Platform 2015-2017
Principal Engineer 2011-2015
Engineering Manager / Bengaluru Dedicated Unit 2008-2011
Senior Network Engineer 2007-2008
  • Managed an eight-engineer platform group for Nova, a cloud-based, live 3D-rendering SaaS platform.
  • Designed the Managed Tiered Proxy Architecture for a rendering pipeline migration from NFS to HTTP.
  • Used Go and TCL to synchronize software deployments and infrastructure configuration updates.
  • Developed Python programs to automate load-balancer and downstream service observability.
  • Relocated to India to oversee a datacenter build and hire systems, networking and tooling teams.
  • Conceived a cross-studio proxy architecture first implemented in India and later adopted globally.
  • Implemented a BGP/OpenVPN solution for 6,000 hosts and designed a TRILL datacenter for STP-free operations.

MobiTV

2005-2007
Engineering Manager
  • Expanded systems and networking teams from 3 to 20 and established a global NOC.
  • Scaled platforms supporting Sprint TV and IPTV launches during extreme channel and client growth.
  • Migrated operations from Rackspace to distributed colocation and secured content ingestion.

First Victoria National Bank

2000-2005
System Architect
  • Established Ethernet-based IP and IPX networking standards for systems and telecommunications.
  • Developed custom applications and retired legacy UNIX systems, saving more than $400K annually.
  • Implemented Tarantella and telecommunications enhancements to improve remote application access.

Information Alliance

1992-2000
Software Engineering Manager 1995-2000
Software Developer 1992-1995
  • Built a team providing Internet connectivity and web-based application development services.
  • Served as a key contributor to FirstPage, a UNIX-based distributed document-processing system.
  • Developed UNIX software for the Criminal Law Attorney Support System, used by 25 Texas counties.

Relevant Skills

Development
C, Go, Python, Rust, TCL, CI/CD, Git, GitHub Actions
Systems
Linux, UNIX, Kubernetes, Mesos, OpenStack, Project Calico, Puppet, Chef, Terraform
Networking
L2-L7, TRILL, STP, BGP, IS-IS, OSPF, TCP/IP, IPsec, HTTP
Education
Texas A&M University, Physics

Past Certifications

  • Novell: NetWare Administrator v3; NetWare Engineer v3, v4 and v5; Compaq Intel/NetWare Specialist (ASE)
  • Red Hat: Linux 7.2 Engineer; Enterprise Linux Engineer
  • Cisco: Cisco Certified Network Associate (CCNA); Cisco Certified Network Professional (CCNP)

Leadership, Service and Recognition

  • Kona House of Palms and Sunrise Hale
    Owner, short-term vacation rentals | 2018-Present
  • Puu Lani Ranch HOA
    Board Member and Website Administrator | 2021-2023
  • Twitter University
    Instructor, Go | 2019-2022
  • Twitter University
    Instructor, Python and the Twitter Build System | 2018-2022
  • San Francisco Site Reliability Engineering Meetup
    Coordinator | 2018-2020
  • DreamWorks
    Technical Achievement Award, Managed Tiered Proxy Architecture | 2014
  • DreamWorks
    Technical Achievement Award, Production Asset Manager | 2014
  • Home of Hope
    Technology Coordinator | 2012-2018
  • Large Scale Production Engineers
    Presenter, "Anycast Service Redundancy and Traffic Balancing" | 2012
  • Aloe Software Group
    Co-Founder, Texas public-school student-management SaaS | 2000
  • VALUE
    Presenter, "The Slackware RPM" | 1998