CV / Resume: Justin Mason

Web: https://jmason.org/ -- Email: jm at jmason.org

OVERVIEW

Principal software engineer experienced in leading the design, development and operation of large-scale software projects.

EXPERIENCE

Systems Architect, Swrve, Inc. (Feb 2013 - Nov 2022) / Principal Engineer, MessageGears Inc. (Nov 2022 - present):

Swrve started off as an A/B testing and analytics platform for mobile games, before becoming a mobile marketing automation platform, and has since been acquired by MessageGears in 2022, who now include it as part of their customer engagement platform.

I have worked on many projects during my time here:

• Designed and built Swrve's scalable, distributed real-time event streaming mesh, handling billions of events per day reliably, with generally sub-second latency, and no known data loss.
• Built an event streaming system using AWS Kinesis, handling reliable high volume streaming ingestion into an Orc data lake for later querying using SQL queries via Presto/Trino/Athena.
• Operability: led the effort to instrument the Swrve codebase with service metrics, and built a set of Grafana dashboards to provide metric-driven alerting and monitoring.
• Built the Swrve standard library for high-throughput web services, allowing both synchronous and asynchronous request handling with Netty, circuit breakers, rate limiting, service metrics, and capacity controls to ensure reliability, operability and scalability.
• Built several high-throughput web services and client libraries for various mobile push messaging protocols.
• Migration of the Swrve platform to containers in order to migrate to Kubernetes and host our production fleet in Amazon EKS.

• Instigated continuous deployment and system tests covering the entire integrated Swrve software stack, using chromedriver and rspec, to ensure release quality. These have now also become a key part of our live production monitoring system, in the form of synthetic monitoring.

SDE 2/3, Amazon.com (Dublin, Ireland) (Jul 2009 - Jan 2013):

As part of AWS, our team developed products and services to perform Amazon-scale active network monitoring.

• My primary project was a next-generation network monitoring system, to detect and triangulate network problems quickly and accurately in order to drive down outage Mean-Time-To-Detect and Mean-Time-To-Recovery. This was composed of a fleet of servers running Jetty and Guice in Java, and lightweight agents running on every one of the millions of physical servers in the EC2 fleet world-wide, written in C++ with Boost. We applied machine learning algorithms to correctly triangulate the root cause of network issues.

Software Engineer, NewBay (Dublin, Ireland) (Dec 2008 - Jul 2009):

• Working on server farm deployment automation, and building large-scale object storage web services in Java.

Software Engineer, PutPlace (Dublin, Ireland) (Nov 2007 - Dec 2008):

• Scaling PutPlace's solutions using Amazon's EC2 and S3 web services; implemented a one-click deployment system to deploy fully production-ready grids of EC2-hosted servers.

VP, Apache SpamAssassin (July 2006 - July 2008), Project Management Committee Member, Apache SpamAssassin (July 2004 - 2014):

• Deciding the architecture, development, goals and direction of the open-source Apache SpamAssassin project. see https://spamassassin.apache.org . This also involved building the spam collection and training infrastructure for the SpamAssassin machine learning component.

SKILLS

Specialities: Java, Linux, AWS, HTTP, TCP/IP, open source, anti-spam, mail, internet security, mail filtering, scalability, data, distributed systems, application performance optimisation

Programming languages, libraries and frameworks: Java, Python, Ruby, C++, C, Perl, sh/sed/awk/etc., AWS, Netty, protobuf, Avro, MySQL, DynamoDB, Presto, Trino, Athena, Parquet, Orc, Docker, EC2, EKS, Kubernetes, Terraform

Development methodologies: XP, Scrum, Kanban

• over 30 years experience working with TCP/IP on various platforms, including HTTP/HTTPS, TLS and SMTP client and server implementations in a variety of languages.
• Have built several highly-scalable web services in Java, using Netty and Jetty.
• Over 15 years experience with AWS services, from EC2 and S3 onwards.
• Created Apache SpamAssassin, the market-leading open-source spam filter product, used by an estimated 100 million users world-wide.
• experience operating and administering a variety of UNIX systems.

• Set up the first non-academic web server in Ireland, the 70th HTTP server in the world.

OPEN-SOURCE SOFTWARE

In addition to the commercial software development experience detailed above, I am the author of a number of free / open-source software projects. Highlights:

• Apache SpamAssassin, a mail filter to detect and block unsolicited bulk email. I created the first version in 2001, and by now it is probably the most widely-used spam filter in the world, protecting around 100 million users world-wide; more info at https://spamassassin.apache.org . As part of this work, we were one of the first to apply machine learning to spam filtering in 2001, using a genetic algorithm (and later a perceptron neural network).

• PLP, a drop-in replacement for the UNIX "lpr" printer system. During my maintainership it eventually had over 10,000 users in over 100 sites. PLP was included in SuSE Linux, among other Linux distributions.

PUBLICATIONS / TECHNICAL TALKS

• Justin Mason, New Features in SpamAssassin 3.2.0 Of Interest To Large Receivers, presentation, MAAWG Dublin 2007: https://cwiki.apache.org/confluence/display/spamassassin/PresentationsAndPapers
• Henry Stern, Justin Mason, Michael Shepherd, A Linguistics-Based Attack on Personalised Statistical E-mail Classifiers. Technical report CS-2004-06, Faculty of Computer Science, Dalhousie University, Halifax, NS, March 2004. http://www.cs.dal.ca/research/techreports/2004/CS-2004-06.shtml
• Justin Mason, Spam Forensics: Reverse-Engineering Spammer Tactics, presentation, Toorcon 2004: https://cwiki.apache.org/confluence/display/spamassassin/PresentationsAndPapers
• Justin Mason, Filtering Spam With SpamAssassin, presentation, HEANet Annual Conference 2002: https://cwiki.apache.org/confluence/display/spamassassin/PresentationsAndPapers

• Prof. Patrick Powell, Justin Mason, LPRng, An Enhanced Printer Spooler System. Paper presented at the USENIX Large Installations Systems Administration (LISA '95) conference. http://www.usenix.org/publications/library/proceedings/lisa95/papowell.html

EDUCATION

1989 - 1990: BA degree in Mathematics, Trinity College, Dublin, Ireland; did not complete degree.