Sumner Evans
Senior Implementation Tech Lead at Can/Am Technologies

Portfolio

Note

This page is my extended Curriculum Vitae containing all my professional achievements. For a more concise overview, please view my resume.

I'm a software engineer and educator. I have six years of industry experience as a software engineer, and I have taught classes at a university level including one graduate level course.

Experience

Senior Implementation Tech Lead

April 2025 - Present

Can/Am Technologies

I joined Can/Am Technologies as a Senior Implementation Tech Lead.

Software Engineer

July 2021 - April 2025

Beeper

Key Technologies: Matrix, Go, Python

I worked on building the infrastructure necessary to connect people on every chat network through Matrix. I worked mainly on bridges and other backend projects to enable Beeper to grow and add new users.

Notable projects include...
  • Scaled our backend infrastructure from handling <1,000 users to >100,000 users by sharding traffic from high-volume bridges to a separate Go service called Hungryserv in a backwards-compatible, transparent manner. I created the initial proof of concept and then continued as a core member of the 3-member team that productionized the project over a four-month period.
  • Saved ~2TB of RAM by rewriting the Telegram to Matrix bridge from Python to Go.
  • Reverse-engineered and implemented features for Beeper Mini (iMessage on Android) including media, tapbacks, typing indicators, read receipts, edits, unsends, link previews, and chat metadata changes.
  • Implemented the cryptographic key infrastructure necessary for message key backups and interactive device verification in mautrix-go. by utilizing the standard Go cryptography libraries.
  • Implemented media upload/download and interactive device verification in the Beeper client SDK written in Go which is being used in the next generation Beeper clients.
  • Measured message send latency and reliability by instrumenting bridge metrics. Built a Dockerized Go service to process those metrics and send them to BigQuery.
  • Streamlined our support team's ability to chat directly with users by building a Chatwoot bot in Go.
  • Reverse-engineered the LinkedIn Messaging API and implemented a LinkedIn to Matrix bridge in Python and later in Go.
  • Defined a framework for importing users' chat history, and implemented it in the WhatsApp, Facebook, Instagram, and Telegram, bridges.

Adjunct Professor

August 2018 - December 2024

Colorado School of Mines

I have had the opportunity to teach courses in multiple areas of computer science at my alma mater, Colorado School of Mines.

Courses I've taught:

Algorithms (4×) — advanced data structures, graph algorithms, dynamic programming, NP-completeness

I taught CSCI 406 Algorithms once while I was a graduate student in 2018 under Dr. Dinesh Mehta. I also taught two sections in Spring 2022 using Dr. Mehta's materials. I co-taught the class with Dr. Mehta in Fall 2023 and Fall 2024.

Full list of topics that the class covers include: analysis of algorithms, advanced data structures, sorting algorithms, dynamic programming, graph algorithms, and NP-completeness.

Programming Languages (4×) — functional programming, parsers, type systems, formal semantics

I taught CSCI 400 Principles of Programming Languages once as a graduate student in 2019. Topics that the class covered at that time include: programming language concepts, evaluation, and implementation; object-oriented programming; Lambda Calculus; and Racket (a LISP dialect).

I then taught the course twice under Dr. Jedidiah McClurg in 2020 and 2021, and once under Amelia Read in Fall 2022. Topics that the course covered in those iterations included: functional programming concepts, type inference, OCaml, programming language implementation, and formal semantics.

Computer Organization (1×) — RISC-V assembly, pipelining, processor design, memory hierarchy

I taught CSCI 341 Computer Organization with Dr. Qi Han in 2023.

Computer Architecture (1×) — cache coherence, virtual memory, branch prediction, multiprocessors

I taught CSCI 564 Advanced Computer Architecture in Spring of 2021. Topics that the class covered included: performance analysis, cache, virtual memory, pipelining, branch prediction, out-of-order execution, and multiprocessors.

I based the course off of the curriculum provided by Dr. Bo Wu and adapted it for hybrid COVID learning. The main additions/changes were adding lecture worksheets to improve student engagement in lectures, modernizing the slides, and reworking the projects starter code to better focus on the learning objectives.

Software Engineer

June 2019 - July 2021

The Trade Desk

Key Technologies: React JS, C#, SQL

I was a member of the Connected TV engineering team. I worked on all parts of the stack including the C# backend, the React frontend, and the SQL Server backend database.

Notable projects included...
  • Implementing ingestion of the ifa_type field in OpenRTB requests across our fleet of high performance bidders. (C#)
  • Building many of the features for the Connected TV incremental reach planning tool. (React, Node.js, C#)
  • Designing and implementing major portions of an AI-powered ad campaign strategy recommendation system. (C#, SQL)
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Software Engineering Intern

May 2018 - August 2018

Pivotal

I worked on the Infra pod on the Tracker team, the team responsible for developing Pivotal Tracker. I anchored the development of a new system for imaging workstations for consistent workflows on all machines used by the Tracker team. I also participated in a LEAN Product process to determine the needs of the Tracker team.

CS@Mines on Tour Presenter

January 2017 - May 2018

CS@Mines Unplugged

I gave presentations to high school students about the Computer Science Department at Mines. I also led computer science related workshops for middle school students.

Teachers Assistant (Data Structures)

August 2017 - May 2018

Colorado School of Mines

I assisted students during TA office hours and during the in-class lab sessions. I was nominated for the Student Employee of the Year by CPW, the faculty member responsible for the course.

Software Development Intern

June 2017 - August 2017

Kenzan

I contributed to OSS projects including React and Node.js on behalf of Kenzan. I also worked to improve the Kenzan.com website by implementing a CI/CD Jenkins pipeline with a WebPack build.

Software Developer

February 2013 - August 2016

Can/Am Technologies

Key Technologies: C#, ExtJS, SQL

I worked on the Teller Development Team designing and building new features for Teller, an enterprise point-of-sale system geared towards municipal governments.

I primarily worked on the web-based application which uses a technology stack consisting of ExtJS (a JavaScript framework), C#, and Oracle PL/SQL, but I also worked on the native Windows application. Additionally, I designed and built plugins that integrate external systems into Teller. One of the more notable plugins I developed was an integration with Bank of America for electronic deposit of checks.

Education

MS Computer Science

August 2018 - May 2019

Colorado School of Mines, 4.0 GPA

I worked with Dr. Dinesh Mehta on a project to automate group selection for projects in CSCI 406 Algorithms.

I served as the Chair of the Mines Association for Computing Machinery (ACM) Student Chapter, the Linux Help Guru of the Linux Users Group, and the Service Chair of the Mines chapter of the Tau Beta Pi Honor Society.

Notable classes I took include...
  • Advanced High Performance Computing
  • Parallel Computing
  • Advanced Computer Architecture
  • Abstract Algebra
  • Theory of Computation
  • Theory of Cryptography

BS Computer Science

August 2016 - May 2018

Colorado School of Mines, 3.9 GPA

I graduated with a degree in Computer Science from Colorado School of Mines. I was awarded the Outstanding Graduating Senior award for Computer Science.

As a student I served one year as the Vice President of the Mines ACM Student Chapter and one and a half years as Secretary of the Mines Linux Users Group (LUG). I made Dean's List every semester of my undergraduate studies.

Notable classes I took include...
  • Operating Systems
  • Algorithms
  • Computer Graphics
  • Computer Simulations
  • Virtual Reality
  • Principles of Programming Languages
  • Artificial Intelligence
  • Software Engineering and Advanced Software Engineering (Field Session)
  • Computer Organization
  • Linear Algebra
  • Data Structures

Mines Transfer Program

August 2012 - May 2016

Red Rocks Community College, 4.0 GPA

Through high school, I took classes at Red Rocks Community College via the transfer program between Colorado School of Mines and Red Rocks. I was a member of the Phi Theta Kappa Honor Society for three years.

I was selected to be published in CLARO an interdisciplinary scholarly journal. I then presented my work at the CLARO academic conference.

Notable classes I took include...
  • Spanish Language I and II
  • Calculus I, II, III, and Differential Equations
  • Chemistry I and II
  • Calculus-Based Physics I and II

Presentations

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Projects

Mines HSPC Website

August 2021 - Present

GitHub | Live Website | AGPLv3+

The Mines HSPC website handles registration for the annual CS@Mines High School Programming Competition. It allows teachers to register teams and manages all of the necessary paperwork for students to be able to participate in the event.

The website uses passwordless authentication and also uses email to verify student emails and send parents the forms they need to sign.

The Mines HSPC website is developed on GitHub and deployed on infrastructure provided by Nevarro LLC.

offlinemsmtp

May 2018 - Present

GitHub | GPLv3+

Read my blog post announcing offlinemsmtp v0.3.5: Introducing offlinemsmtp.

offlinemsmtp allows you to use the msmtp SMTP email sending program offline. While offline, it enqueues emails to be sent once an internet connection is established. While online, it sends the emails immediately.

offlinemsmtp is written in Python, and is available via PyPi and on the AUR.

Sublime Music

November 2018 - December 2024

GitHub | Website | GPLv3+

Sublime Music is a native, GTK3 Subsonic, Airsonic, Revel, Gonic, Navidrome, client for the Linux Desktop that is written in Python. Sublime Music allows users to connect to multiple Subsonic API-compliant servers, and browse and play music from those servers.

Other features include being able to play music through Chromecast devices on the same LAN; Offline Mode and the ability to cache songs for offline listening; a DBus MPRIS interface integration for controlling Sublime Music via playerctl, i3status-rust, KDE Connect, and other DBus MPRIS clients; a sophisticated play queue; playlist management; and more.

I began this project after migrating to Airsonic for music hosting because I was dissatisfied with the existing Airsonic clients on Linux.

Sublime Music is developed on GitHub and is available via the AUR, NixOS 20.09, Debian Testing, and PyPi.

Visplay

February 2018 - May 2020

GitLab | GPLv3+

Visplay is a Mines ACM project. It's goal is to create a digital signage system with a dynamic, hierarchical configuration system which can be used in a wide variety of hardware and infrastructure configurations.

I worked on the initial design of the overall architecture of the project. I have also contributed in a project management role. I worked on the Python components of the project which consume the configuration files and generate playlists. I also led development of the web configuration frontend.

Currently, I am working in an advisory role as an industry project mentor.

MLocate

February 2019

Second Place | GitLab | AGPLv3+

This project won Second Place at HackCU V.

Read my blog post about this hackathon: HackCU V.

MLocate is a comprehensive system for tracking and locating devices within an indoor space just using Wi-Fi ping signals. Using three specially configured Wi-Fi access points, we were able to capture signal strength from every device in the room by MAC address. Then, applying Radio Signal Strength Indication (RSSI) models, we were able to derive distance from signal strength which allowed us to use standard triangulation algorithms for determining the location of all of every device in the room.

I worked on the triangulation logic for pinpointing device locations given distances calculated from signal strength. I also built the web frontend for displaying device locations.

MLocate was a hackathon project by Ben Perkins, Jesus Nuñez, Nick Jarmusz, (all freshmen) and myself. We developed it during a 24 hour period at the HackCU hackathon.

HypAR Map

November 2018

First Place | Demo | GitLab | AGPLv3+

This project won First Place at the Facebook Global Hackathon Finals at Facebook HQ.

Read my blog post about this hackathon: Facebook Global Hackathon Finals - The Competition.

HypAR Map helps users navigate around unfamiliar locations by overlaying a map of the area using augmented reality. The map can come from any photo (for example, a fire escape plan) and is calibrated using an intuitive user interface. HypAR Map then uses simultaneous location and mapping to find and display the location of the user in the map in real-time.

I worked on the image import functionality and worked with all of the members of the team to ensure that everything connected properly.

HypAR Map was a hackathon project by Sam Sartor, Jack Garner, Fisher Darling, and myself. We developed it during a 24 hour period at the Facebook Global Hackathon Finals at Facebook HQ in Menlo Park, CA.

CS@Mines Demo at Facebook Global Hackathon Finals
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BlockMRS

January 2018

GitHub | GPLv3

BlockMRS is a privacy concious, decentralized, blockchain-backed, medical record system for the 21st Century. It stores patient records in IPFS using asymmetric encryption giving patients control over their health data.

I led the development of the protocol specification for this decentralized system. I also built the system for storing encrypted medical records in IPFS.

BlockMRS was a hackathon project by David Florness, Jack Rosenthal, Robby Zampino, and myself. We developed it during a 24 hour period at the MinneHack 2018 hackathon.

Parqyng

October 2017

Grand Prize | Demo | GitHub | MIT

This project won the Grand Prize at the 2017 Xilinx PYNQ Hackathon.

Parqyng Lots tracks the number of cars in an arbitrary number of parking lots with an arbitrary number of entrances to create an up-to-date picture of the parking situation.

I built the web frontend which provided a view of the parking lots' status.

Our team consisted of Sam Sartor, Jack Rosenthal, Daichi Jameson, and myself. I worked on the web interface and also helped implement the tracking system using the sensors provided by Xilinx.

Parqyng: Never Look for a Parking Spot Again

Publications