Tom Calloway
Senior Software Engineer
Address
Rua Das Cegonhas NR89 HB4.1
Porto,-, Portugal
LinkedIn
https://www.linkedin.com/in/tomcalloway
Phone
- | -
E-mail
-
GitHub
https://github.com/modellurgist
Together with our team, I will help discover product and scaling needs highly-valued by our customers,
imagine conceptual and technical solutions, persevere beyond implementation obstacles, actively seek
improvements, materialize cost-effective features that are simply-expressed in tested code, and then
measure how user, business, and system metrics improve.
Skill Set
Languages
Elixir, Ruby, Clojure, Elm, Javascript, HTML, CSS, Python
Frameworks
Phoenix, Rails, Elm, React, dry-rb, Svelte, re-frame, Hanami, Ember
Database/Operating Systems PostgreSQL, Datomic, MySQL, Mac OS X, Ubuntu
Deployed Environments
Heroku, AWS, Kubernetes, Gigalixir
Experience
Fluxgate Inc. Porto, Portugal
Senior Software Engineer
May 2019 – Present
●
Launching diverse online products into hypothetical customer problem spaces using Elixir, Phoenix, and
Svelte.js, taking from concept through design, development, content marketing, and Google Ad campaigns,
to post-launch analysis, solution validation, variant experiments, and pivots.
●
Refining an interactive, functional-style Ruby guest framework (portable to Phoenix) that speeds up
launches by reducing the necessary amount of custom code after generating tests and dynamically creating
views, styles, and controllers from the encoded application configuration and user interactions.
Eat To Perform Remote
Senior Contract Engineer
September 2018 – May 2019
●
Reached parity with legacy Rails API by expanding functionality of Clojure back-end Lacinia GraphQL API,
storing to a Datomic database and pulling via custom HugSQL from a legacy MySQL database.
●
Cut third-party callback response times by offloading async work, increasing success rate from 92% to 99%.
●
Generated statistics for customer compliance with each nutrition plan element, yielding quantitative factors
to correlate with customer success and retention rate.
●
Built user visualization in Clojurescript React (re-frame) app to track plan compliance and developed logic
for Kubernetes cron jobs to generate internal reports that locate deviant service-wide or customer-specific
behavior.
●
Set-up RabbitMQ exchange, consumers, and producers in Rails and Clojure, to process APNS iOS
notifications.
●
Integrated mechanism and custom handlers for detection and auto-correction of sign-up and other
conditions that could partially-fail third-party API data fetches, including notifications to Slack for tech
support follow-up.
●
Refactored and simplified data source reconciliation code to use a consistent calculation and also improved
production console inspection functions, to quickly inspect source reconciliation or partial data issues.
●
Simplified data flow between legacy and primary APIs/DBs, to reduce data discrepancies.
Home Chef Chicago, IL
Senior Software Engineer
March 2017 – September 2018
●
Built v1.0 of "Smart Ice" Rails logic, to calculate the requisite quantity of ice packs to preserve boxed
meal-kits based on the local weather of delivery destinations.
●
Took prototype, re-wrote in Rails, and shipped the team's first tablet web app to track meal bag production
rates.
●
Constructed and enhanced additional Rails tablet apps, to monitor quality, ingredient portioning and
combination; and summarized that data in a React dashboard app to show real-time progress and risks.
●
Crafted multiple scalable Ruby service objects, including failover cases during large re-write of shipping
label and packing slip batch jobs, achieving faster execution, persisted intermediate calculations,
greater reliability, fault-tolerance, and extensibility.
●
Built, monitored, and managed interdependent Sidekiq-Resque background jobs during critical operation
periods.
●
Built out scan-and-print Ruby codebase to support trackable application of shipping labels on meal-kit
boxes, including Ubuntu OS configuration and application installation automation.
FluxGate LLC Chicago, IL
Software Engineer
February 2017 – July 2017
●
Delivered iterations for client's applications and for new products validated through lean customer
development.
●
Built a custom functional-style Ruby framework that nests, inside a Hanami umbrella web app (portable to
Rails), an application-specific gem leveraging dry-rb and rom-rb to contain the data model and domain logic
and to define the application UI structure, flow, content, and style and its event handlers all as configuration
data, to orchestrate generic code that fulfills controller, view, and model responsibilities.
eSpark Learning Chicago, IL
Senior Software Engineer
June 2016 – February 2017
●
Built, to precise designer specifications, React client app and Rails API features identified by lean customer
discovery for an in-classroom, project-based learning experience incorporating authentic expression,
autonomy, peer and teacher feedback, structural aids for writing, and differentiated learning.
●
Improved market fit and funnel metrics for a free trial by developing and measuring iterative prototype,
content, flow, and feature variants.
Groupon Chicago, IL
Software Engineer
August 2011 – May 2016
●
Developed high-value features for a flagship consumer-facing web app that promotes deals for an arbitrary
number of featured and ongoing special occasions, reaching page view daily peaks between 10k – 100k
rpm.
●
Built sales lead sourcing and deal geographic dispersion analysis/scheduling internal Rails apps.
●
Iterated high-adoption Rails app to support merchant sales interactions and deal creation workflow
(DealWizard).
●
Enhanced A/B experiment configuration Rails API and Ember client-side app to monitor experiment
progress.
●
Built data entry web apps and NLP mining algorithms in Clojure and Python, to identify optimal deal
structures.
FluxGate LLC Chicago, IL
Software Consultant
TKML Chicago, IL
Application Developer
●
February 2011 – August 2011
Engaged by major retailer to pair-program well-tested feature sets for a web marketplace and B2B API, in
Rails.
March 2010 – February 2011
●
Developed a unified lead engagement Rails web app with a small Agile team, to provide a major insurance
client's staff with access to new leads captured from printed cards and diverse electronic sources, fairly
assigning leads to independent local agents, tailoring call scripts, and guiding agents to qualify, track, and
report leads.
●
Led efforts to introduce Agile practices: user stories to capture extensive requirements, outside-in
behavior-driven development, expressive responsibility-driven object design, pair-programming, and
refactoring.
●
Maintained static content updates to a Rails app that provided agents with detailed marketing advice for a
target customer and product, translating the design team's Photoshop content into HAML views and
SASS/CSS styles.
Stark Investments Milwaukee, WI
Software Engineer Intern
April 2008 – November 2009
●
Extended and supported a legacy JRuby on Rails app to periodically send parameterized Back Office
reports with optimized SQL queries from trading databases to Finance, Reconciliation, Settlements, and
Valuations teams.
●
Pair-programmed with mentors to learn Ruby language idioms, the Rails framework, tight requirement
scoping, lightweight object-oriented and domain-driven design, test-driven development, refactoring, and
troubleshooting.
WI Department of Natural Resources Air Management Engineer
●
March 2000 – November 2006
Performed factory air emissions calculations, analyzed rule applicability and limits, and drafted permits.
Education
Master of Science, Computer Science
University of Wisconsin-Milwaukee
Cumulative GPA: 3.6 / 4.0
December 2009
Decision Support Systems and Groupware, Computational Social Choice, Data Mining, Artificial
Intelligence, Algorithm Design and Analysis, Information and Coding Theory
Bachelor of Science, Chemical Engineering
Purdue University, West Lafayette, Indiana
Languages
English, German, Cantonese, Portuguese
Cumulative GPA: 3.3 / 4.0
May 1999
