William Herrin's RESUME
I am a computer networking generalist with deep expertise in network
protocols, resilient and scalable Linux software development, C programming,
UNIX and Linux systems administration, and Internet security. I have a
broad knowledge base, I chase new knowledge deep to mastery, and I am
diligent and thorough in my work.
I seek a small company or a small independent team within a larger company
where I can funnel my experience through my creativity and invent useful things
which expand the edge of the possible. I desire roles which are heavy on
creative problem solving, requiring both deep insight in to and mastery of the
given subject matter as well as sufficient breadth of skill to chase any
problems to the root cause. I prefer roles with a mix of system operations and
Dirtside Systems LLC (Seattle, WA)
Owner, April 2022 - present
- As an expert consultant, assisted clients with thorny
technical challenges related to Linux and networking.
- Work for the Center for Applied Internet Data Analysis (CAIDA)
at the San Diego Supercomputer Center.
- Assisted research scientists understanding
the nuances of common network protocols
including Anycast BGP Routing combined with TCP.
- Investigated and addressed flash write
mitigation issues on the fleet of Raspberry Pi
Internet data collectors.
- Updated and packaged legacy software for
Debian Linux for use in a continuous integration
/ continuous deployment (CI/CD) system.
- Implemented multiple-architecture software
builds from Git using Docker and QEMU.
- Designed and implemented a conditioned server closet
suitable for one rack-mount cabinet.
- Built a raspberry-pi controlled winter
cold-air bypass for the server closet.
Anduril Industries (Seattle, WA)
Senior Software Engineer, February 2021 - April 2022
- Architected replacement mission comms for the Space Force's
Space Surveillance Network. Used a publish/subscribe software
model under NixOS Linux, redundant ground and satellite TCP/IP
pathways and Viasat HAIPE encryptors. Employed techniques such
as TCP stream interception and Linux network namespaces to
transparently interface with the legacy comms endpoints for a
safe period of parallel operation with the incumbent system.
Employed the Babel routing protocol to automatically use the
best available network pathways between sites.
- Designed and prototyped the network link layer for a
device-agnostic self-constructing mesh network. Used Linux
network namespaces, IEEE Macsec, Google GRPC, Golang and Bash. The prototype
formed an optimal set of encrypted layer-2's based on the
dynamic proximity of each piece of equipment to its peers.
Machines self-constructed the network addresses and architecture
starting with only an identity and an initial shared
- Wrote extensions to Free Range Routing's Babel protocol
module in C. The FRR extensions imported external wireless
signal quality knowledge for use in packet routing decisions.
- Championed and initiated an effort to create a DISA STIG
(Security Technical Implementation Guide) for NixOS Linux.
- Mentored junior staff, teaching the finer points of TCP/IP
networking, Linux software, network security and DoD security
Facebook (Seattle, WA)
Production Engineer, March 2020 - November 2020
- Member of the operating systems team responsible for the
fleet of Linux servers.
- Wrote an
automation safety plugin for Red Hat's DNF software
- Automated large-scale software deployment and configuration
in Chef (Ruby).
- Built system management tools in Bash and Python.
Amazon Web Services (Seattle, WA)
Senior Software Engineer, November 2018 - November 2019
- Worked on the data plane team for Global Accelerator, a load
balancer with BGP-anycasted global entry points.
- Wrote high performance Internet packet handling code in C
using Intel's DPDK framework.
- With deep research, solved a TCP throughput degradation that
bedeviled the first release due to an unexpected secondary
effect from network address translation.
- Led design of a core part of the source address preservation
effort, delivering packets to customers without obscuring the
original Internet source.
- Managed devops and software deployment including
participation in a 24/7 operations on-call rotation.
Tesla Government, Inc. (Vienna, VA)
Devops Lead, April 2017 - October 2018
- Transitioned a system from a physical rack environment to
Amazon Web Services' Govcloud, including VPCs, Red Hat Linux and
Windows 2012 EC2 instances, AWS security groups, Route 53 DNS,
MySQL RDS databases, etc.
- Designed the AWS Virtual Private Cloud (VPC) to overcome
routing limitations so that all data traffic was forced through
appropriate EC2-based security appliances.
- Built Perl software which interacts with the Amazon IAM APIs
and Microsoft Active Directory to implement password changing
and multifactor authentication compliant with NIST Special
Publications 800-63 revision 3 and 800-53 draft revision 5. This
included collecting and implementing a database of more than 17
million compromised password patterns which are used to reject
- Implemented Microsoft Active Directory with custom software
in C for the Linux servers to rely on Active Directory via LDAP
for passwords only.
- Implemented Linux shell users by creating a Red Hat RPM
package for each.
- Implemented compliance with DoD's Risk Management Framework
based on NIST Special Publication 800-53 revision 4 with
Identity and Authentication inserts from draft revision 5.
- Shepherded the new system from concept through the full DoD
Authority to Operate (ATO) and Final Operational Capability
(FOC) process including continuous monitoring with ACAS/Nessus.
- Designed a Continuous Integration / Continuous Deployment
(CI/CD) process using git, Jenkins, Red Hat packages (RPMs) and
- Using a combination of Linux iptables logging rules, Snort
and Splunk, implemented a Network Intrusion Detection System
(IDS) based on building a profile of expected data traffic and
alerting on packets which fail to fit the profile.
- Implemented a primary system firewall using Linux and
iptables, with remote access to the system using OpenVPN.
- Implemented automatic backups for Mac OSX laptops using
shell scripts, network drives and Time Machine.
University of Maryland University College. (Adelphi,
Linux Engineer III, April 2016 - March 2017
- Member of a team supporting a large Amazon Web Services
(AWS) cloud deployment including EC2 virtual servers, Amazon
virtual private cloud networks, security groups, elastic load balancers and Route
- Managed Apache Tomcat Java web servlet containers. Wrote a
health check servlet in Java which checked
operation of multiple servlets in a background thread and
reported a consolidated status to the AWS load balancers.
Dirtside Systems, Inc. (Falls Church,
Owner, May 2014 - April 2016
- Contractor supporting software development for
unusual computer network applications.
- Work for undisclosed company.
- Major network security work including expansive use of
Linux iptables, ip rules, multiple routing tables and
SELinux for server hardening
- Supported pure software developers, mentoring to help them
understand operations-level needs and requirements.
- Wrote glue code in Perl and Python, integrating
disparate software systems
- Some work with Asterisk VoIP servers and SIP trunking
- Some work with Raspberry Pi-based embedded systems
- Designed specialty VPN solutions based on OpenVPN and Cisco Anyconnect.
- Work for Digital Globe Marine Services.
- Worked on the Orb Map fish finder back end Linux system
including cloud virtualization
- Wrote and deployed daily production system using Perl.
- Established custom networking and email services connecting
ships with satellite modems to the data source.
ITT Exelis (Dulles, VA)
Principal Engineer, March 2010 - April 2014
- Led the design and implementation of a resilient computer room with standard n+1 power
and air conditioning systems, as well as the structured cabling system for a company
- Built a "distributed responsibility" developer network, facilitating
development of many Internet-connected products. Compartmented systems accessed via VPNs
from engineers' desks permitted parallel development of systems with divergent security
architectures. Included a building-wide roaming wifi network.
- Built a network of more than 70 virtual machines distributed through a dozen countries.
- Designed and built a system for managing hundreds of millions of
geographic map imagery tiles using C, Perl, some Python and the Linux FUSE
- Defined HTTP-based service oriented architecture APIs for a large
- Built two more BGP-using multi-site continuity of operations networks
- Managed a team of three engineers responsible for around 100 servers, routers and
switches serving multiple government projects.
ITT (Dulles, VA)
Senior Software Engineer, May 2008 - March 2010
- Architected, led the implementation and delivered a geographically diverse (Virginia
& Hawaii) continuity of operations system for an Iridium satellite base-end station.
Used Linux LVS load balancers controlled by custom Perl-based software to
access active-active redundant servers. OSPF and Quagga attached IP
addresses to the active firewalls while BGP brought packets into the network
at both sites.
- Implemented a thorough hardware and software monitoring and reporting system
comScore, Inc (Reston, VA)
Senior Software Engineer, November 2007 - April 2008
- Developed a Linux-based network appliance that
captured and analyzed HTTP packet traffic.
Democratic National Committee (Washington, DC)
Internet Infrastructure Manager, September 2005 - November 2007
- Managed a staff of three engineers responsible for 70+ Linux servers used by three
Democratic Party organizations.
- Designed and built a resilient computing infrastructure including two collocation data
centers, a 56-mile fiber optic ring connecting them with national headquarters, multiple
Internet backbone connections and BGP reciprocal peering.
- Implemented thorough hardware monitoring and reporting to identify and replace ailing
servers before they break.
- Helped specify and deploy an Avaya VoIP phone system for 300 users.
- Performed professional management in the following areas: computer/system operations,
systems administration, communications network administration, software development,
systems software support, hardware support, database administration.
Cambridge Communications Systems, Inc. (Suitland,
Research Analyst - Linux, December 2004 - September 2005
- Contractor for the United States Bureau of the Census, Telecommunications Office.
- Designed and built custom spam control software using Sendmail, multi-threaded C and
Perl with individual customer settings and an intelligent recovery method for false
Democratic National Committee (Washington, DC)
Senior Information Technology Generalist, August 2004 - December 2004
- Helped the DNC scale up their Internet operation for the 2004 election. Rebuilt the link
redirector part of the web application that couldn't withstand the higher load.
- Constructed an online UNIX backup solution that backed up multiple terabytes of data and
successfully restored data following several database crashes and an accidental file
CrossLink Internet Services (Springfield,
Director of Engineering, November 1998 - May 2004
- Led a team of three engineers to construct and maintain a wide area network (WAN) and
Internet server system deploying Cisco, UNIX, and Windows Server technologies.
- Developed and deployed server-based E-Mail antivirus software using multi-threaded C and
Perl on a Linux platform.
- Constructed robust network monitoring software suitable for identifying faults in and
notifying operations staff in an Internet Service Provider network consisting of more than
40 sites in 5 states and more than 200 Cisco routers, including a multihomed BGP backbone.
- Performed cost analyses on proposed company products. Assisted sales staff with product
netFilter Technologies (Falls Church,
Co-owner, August 1996 - November, 1998
- Lead developer on a network-hosted HTTP web content filter.
Why? Internetworking (Annandale, Virginia)
Owner, October 1995 - August 1998
- Developed and operated all World Wide Web services for CrossLink, a regional Internet Service Provider.
Office of Naval Research, Ocean Acoustics Program
Office Automation Clerk, June 1993 - September 1996
- College internship involving Sun Solaris system administration including
shipboard support during experiments.
More information is available.
George Mason University (Fairfax, Virginia)
Bachelor of Science in Computer Science, January 1997
GPA - In Major: 4.0, Overall: 3.3
More information is available.
- A quarter century of professional software development experience.
- Programming Languages: Expert: C and Perl. Experienced: Unix shell
scripting. Minor or out of date experience in many others.
- Robust software development skills. I learn new programming languages
- Expertise in both single-threaded and multi-threaded programming.
- Experience developing software for MySQL. Minor experience with other SQL databases including Postgres, Oracle and Netezza.
- Extensive Internet-related expertise.
- Recognized Internet routing expert.
- Strong experience with BGP and
BGP AS 11875 announcing 22.214.171.124/23 using Free
Range Routing (FRR), Quagga and Cisco routers.
- Participated in the Internet Research Task Force's Routing
- Participate in the American Registry for Internet
Numbers' public policy process.
- Credible run for election to the American Registry for Internet
Numbers Board of Trustees:
earned 73 votes out of 138 needed.
- Developed an
experimental routing overlay leveraging GRE and DNS.
- Designed and prototyped a base layer for a
high-scalability self-constructing mesh network.
- Estimated the
cost of BGP's scalability problem.
- TCP/IP expert including development of software applications using
IPv4, IPv6, TCP, UDP, IP, ICMP,
DNS, GRE and VPNs.
- Experience with Software Defined Networking (SDN) and the Intel
Dataplane Development Kit (DPDK) framework
Did theoretical design work on a resilient
anycast TCP solution that
is able to continue the TCP connection even when a customer’s
packets are split between multiple nearest servers.
- Hosted Internet Domain Names (DNS) using ISC Bind since
1993. Used DNS as the map resolver for an
experimental routing protocol
including low-level work on DNS packets in C. Did theoretical
design work on DNS-specific stateless anycast TCP.
- Broad experience with Cisco routers including automated updates and
management via SNMP and telnet. Built software which automatically backs
up the router configurations. I have used IOS 10.0 through 15.
- I've worked with a variety of data circuits including: POTS lines, ISDN BRIs (ni1), ISDN
PRIs (5ess and dms100), T1s, T3s, frame relay, ATM, CWDM, dark fiber, various
technologies and 802.11 wireless.
- Three decades of experience developing software in UNIX environments including Linux (SuSE,
Red Hat, Fedora and Debian), Sun Solaris, Dynix, Ultrix, Irix and HP/UX.
- Deep understanding of Internet security technology including firewalls, packet
filtering, NAT, Unix security, content filtering (anti-porn, anti-spam) and encryption
including IPSec, SSL/TLS, and LDAP.
- Extensive expertise with Internet mail protocols including SMTP, POP, and IMAP. Have
written delivery agents, spam and virus filters, glue code and helper programs for major
software packages including Sendmail and Postfix.
- US Citizen. Hold an active DoD Top Secret clearance.
Held SCI eligibility in the past.
- Fully vaccinated.
- Open to in-office, remote and hybrid work. Some travel OK. No
References and work samples are available on request.
Monday, May 22, 2023 08:44 PM.