Sean Jain Ellis
Site Reliability Engineering - Infrastructure - Distributed Systems
Principal engineer with 30+ years of experience architecting and operating
large-scale, mission-critical infrastructure and distributed systems. Deep
expertise across networking, systems and software development. Proven
technical leader with a track record of solving complex infrastructure
problems and driving engineering excellence across teams.
Engineering Highlights
- Automated and standardized golden signal alerting at Upstart, improving
incident detection times
- Led Twitter’s system resource management initiative, with $200M+ in
projected CapEx savings
- Designed a network access control policy management platform at Box
- Developed automated service monitoring and observability dashboards at
DreamWorks Animation
- Designed a network and systems configuration management platform at First
Victoria National Bank
- Key contributor to OnDataSuite, a student management SaaS platform, at Aloe
Software
- Unix developer for the hot check management system within CLASS, used by
Texas district attorneys
Upstart
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| Principal Site Reliability Engineer |
2023 - 2025 |
- 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 as means to enhance change
documentation
- Aligned Compliance and Engineering incident management pipelines onto a
single tracking platform
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| Staff Site Reliability Engineer / Storage Technical Lead |
2020 - 2023 |
- Led a system resource management initiative with $200M+ 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
- Migrated storage support services from Mesos to Kubernetes, and from
Python to Go
- Key contributor to implementing RocksDB for Manhattan, Twitter’s key-value
database
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| Engineering Manager / Real Time Storage SRE Teams |
2018 - 2020 |
- Managed 6-8 direct reports embedded within two teams of ~35 storage
software developers
- Directed a Python v3 migration ahead of the v2 EOL; moved 300MB of legacy
code to a monorepo
- Achieved 85% at-rest and 100% in-transit encryption adoption, with 50%
mTLS coverage
- Developed promotion documents with all engineers, 1 promotion from senior
to staff
Box
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| Staff Site Reliability Engineer |
2017 - 2018 |
- Designed a distributed firewall for Linux hosts, Kubernetes, OpenStack and
network gear
- Standardized edge proxies on NGINX from a mix of Apache Traffic Server and
HAProxy
- Developed a traffic monitoring service, used to validate network access
controls
DreamWorks Animation
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| Engineering Manager / Nova Rendering SaaS Platform |
2015 - 2017 |
- Managed the platform group of 8 engineers for Nova, a cloud-based live 3D
rendering SaaS
- Migrated services from HPE Helion to Rackspace managed OpenStack
environments
- Strengthened incident response procedures for coordination with external
partners and customers
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| Principal Engineer |
2011 - 2015 |
- Designed a managed proxy architecture to migrate rendering pipelines to
HTTP from NFS
- Wrote Go software to synchronize software deployments and infrastructure
configuration updates
- Developed Python programs to automate load balancer and downstream service
observability
- Assembled proof of concept rendering environments with manycore processors
and GPGPU
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| Engineering Manager / Bengaluru Dedicated Unit (India) |
2008 - 2011 |
- Hired network, systems and tooling engineers (10-15 in total) for a new
studio
- Oversaw the initial build and expansion of a datacenter with 25,000
servers
- Conceived a cross-studio proxy architecture, implemented for India, later
adopted globally
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| Senior Network Engineer |
2007 - 2008 |
- Automated an OpenVPN and BGP solution for 6,000 listeners
- Implemented TRILL within a datacenter for switching operations without
spanning tree protocol
- Updated routing protocols from OSPF to BGP and switching redundancy from
RSTP to MSTP
MobiTV
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| Engineering Manager |
2005 - 2007 |
- Expanded systems and networking teams from 3 to 20; established a global
NOC
- Scaled platforms critical for Sprint TV and IPTV launches, during extreme
channel and client growth
- Migrated operations from Rackspace to distributed colocation; secured
content ingestion
First Victoria National Bank
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| System Architect |
2000 - 2005 |
- Established Ethernet-based IP and IPX networking standards for systems and
telecom
- Developed custom applications and decommissioned legacy Unix systems,
saving $400+k annually
- Implemented Tarantella and telecom enhancements to optimize remote
application access
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| Software Engineering Manager |
1995 - 2000 |
- Assembled 3-5 systems engineers and developers for a B2B Internet services
team
- Oversaw software projects that replaced more than 200 Unix implementations
with Linux solutions
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| Software Developer |
1992 - 1995 |
- Key contributor to FirstPage, a Unix-based document processing system for
distributed companies
- Unix developer for CLASS (Criminal Law Attorney Support System), used by
25 Texas counties
Relevant Skills
- Development: C, Go, Python, Rust, TCL; CI/CD, git, GitHub Actions
- Systems / Services: Linux, Unix; Kubernetes, Mesos, Openstack, Project
Calico, Puppet, Chef, Terraform
- Networking: L2-L7: switching (TRILL, STP), routing (BGP, IS-IS, OSPF),
TCP/IP, IPsec, HTTP
- Formal Education: Texas A&M University, Physics
Past Certifications
- Novell: Novell NetWare Engineer (v3, v4, v5), Compaq Intel/NetWare
Specialist (ASE)
- Red Hat: Linux 7.2 Engineer, Enterprise Linux Engineer v2
- Cisco: Cisco Certified Network Professional (CCNP)
Other
- Kona House of Palms and Sunrise Hale: Owner of 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: Co-Founder for a public school student management SaaS,
2000
- VALUE (Victoria Area Linux and Unix Enterprises): Presenter, The
Slackware RPM, 1998