Will Sheehan, Developer in Plainfield, NH, United States
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Will Sheehan

Verified Expert  in Engineering

Software Developer

Plainfield, NH, United States
Toptal Member Since
October 18, 2019

Will is a seasoned full-stack developer who possesses deep experience with data-rich and stateful applications due to having developed high-speed trading systems and interfaces at a prop trading firm. He is a polyglot developer who enjoys working with many different programming languages to write simple-but-powerful software



Preferred Environment

Git, MacOS

The most amazing...

...thing was making a parallelized trading strategy simulation engine for a hypothesis analysis across hundreds of markets using a high-fidelity sub-second market.

Work Experience

Full-stack Engineer | Quantitative Developer

2017 - 2019
Citizen Hex
  • Built a trading style UI for monitoring and performance analysis in React. The app ingested large amounts of streaming data into stateful components requiring high performance and clean state semantics.
  • Developed a backtesting and data-ingestion engine for the strategy testing and backward analysis in Python and Julia—leveraging Spark as a parallelism layer to handle TBs of data.
  • Implemented pieces of a distributed suite of trading microservices in Node.js, in particular, the order placement/execution and data ingestion layers.
  • Led research on algorithmic market-making bots across 100+ trading pairs.
  • Created a highly fault-tolerant order management system.
Technologies: BigTable, Spark, Python, JavaScript, React, Node.js

The Majority Report

A reference for all things reporting in the Augur protocol.

Augur is a predictions market on Ethereum and the reporting process determines how the predictions resolve. The Majority Report is a React-based app that connects to an Ethereum scraping GraphQL back end and an Elixir backend for non-Ethereum data.

Green Hope Farm

I built an eCommerce site for flower essences with a custom Redis shopping cart and admin interface. It was all built with Ruby on Rails.


A simple trading bot built with Elixirs supervision tree to deliver clean trading semantics. This is a simple example of a trading bot (all my complex bots are proprietary).

College Guild

An internal admin management system for a non profit built from scratch with Ruby on Rails. The system allowed for CRUD operations on thousands of users and a meta reporting protocol that allowed for admins to create custom reports from the database.

Dedalus CI

A continuous integration cluster that runs a Jenkins server that boots Docker containers and parallelizes computationally intensive fluid dynamics simulations. The tests, therefore, had to look for accurate structure only because testing for explicit correctness was impossible within a simulation. The architecture was custom built to be performant and to serve the needs of the team of scientists it served!


JavaScript, Ruby, Elixir, Python, Julia


React, Node.js, Pandas, D3.js


Ruby on Rails (RoR), Phoenix, Spark


Functional Programming


Docker, MacOS




PostgreSQL, BigTable, MongoDB, Amazon S3 (AWS S3)

2013 - 2017

Bachelor's Degree in Physics

Bates College - Lewiston, ME, USA

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