My name is Josh. I work on all things scientific/technical computing, but my niche is the intersection of statistics and computer science. I’m good at solving problems and then converting whiteboard math into efficient programs. Julia is my favorite language. During my PhD I researched online (a.k.a. streaming or single-pass) algorithms for statistics (see OnlineStats.jl). I spent 8 years at JuliaHub working primarily on large government-funded projects (Air Force, DARPA, In-Q-Tel, etc.). In November 2025 I became the Director of Software Engineering at Rallypoint One where I am the PI for a variety of (mostly) federally funded programs (Navy SBIR, NSF).

Things I’ve Built

Products

  • One Click Tuner: Chromatic musical instrument tuner for iOS.
  • TrendSpot: Keyword research tool.

Open Source

All created in the time before AI assistants.

Package Description Stars
OnlineStats Single-pass algorithms for statistics
PlotlyLight Lightweight Plotly.js interface for Julia
XML Fast XML parser for Julia
AverageShiftedHistograms Kernel density estimation for big data
Cobweb HTML templating and components for Julia
XKCD Fetch XKCD comics from Julia
SparseRegression Penalized (Ridge, LASSO, etc.) regression

Many more projects on GitHub.

Closed Source

  • Web API for NLP (Natural language processing).
  • Web app and backend for time series analysis based on news article NLP (sentiment, entities) of various sources.
  • Full stack development of web app for analyzing test flight data.

Education

Degree Year Institution
PhD Statistics 2018 NC State University
MS Statistics 2014 NC State University
BS Math & Statistics 2012 Winona State University
BA Economics & Music 2009 Winona State University

Work History

Director of Software Engineering at Rallypoint One (Oct 2025 - Current)

  • Principle Investigator for federally funded programs (NSF, ONR).

Senior Research Scientist at Julia Computing (Oct 2017 - Oct 2025)

Data Scientist II at Valassis Digital (Aug 2019 - Oct 2019)

  • Researched use cases for streaming data models in Ad Tech.

Data Scientist Intern at MaxPoint (May 2015 - Aug 2015)

  • Developed on-line algorithms for advertising retargeting (logistic and survival models).
  • Fitted many Scikit-Learn models.

Statistical Development Intern at SAS-JMP (May 2013 - May 2014, May 2015 - May 2016)

  • Researched methods being considered for JMP platforms (Bayesian and DOE).
  • Wrote test suites using JMP Scripting Language (JSL) for validating statistical results.
  • Led development of redesigning the JMP Starter.

Statistics Consultant at Winona State University (Jan 2012 - Aug 2012)

  • Assisted students and faculty with experiment design, data analysis, and visualization.

CRM Analytics Intern at Best Buy (May 2011 - Sep 2011)

  • Planned and analyzed A/B experiments using SAS and SQL.

Selected Talks

Slides and other materials available at https://github.com/joshday/Talks.

  • Using Julia on Large, Streaming Datasets: Julia Computing Webinar March 2020 (youtube)
  • Scalable Data Analysis with JuliaDB and OnlineStats: JuliaCon 2018 (youtube)
  • SparseRegression.jl: Linear Models with Sparse Coefficients: JuliaCon 2017 (youtube)
  • Sorting Algorithms: NC State, ST 758: Statistical Computing (Fall 2017)
  • Online MM Algorithms for ML: International Chinese Statistical Association Conference 2016
  • Julia for Modern Data Analysis: PyData Carolinas 2016
  • OnlineStats.jl: Online Algorithms for Big and Streaming Data: JuliaCon 2016 (youtube)
  • Overview of Stochastic Gradient Descent: NC State Statistical Learning Group (Fall 2015)
  • Intro to Julia: NC State, ST 758: Statistical Computing (Fall 2015)
  • Intro to R and RCpp: NC State, ST 790: Advanced Computing (Spring 2015)
  • Online Optimization: NC State, ST 790: Advanced Computing (Spring 2015)
  • Penalized Methods: Ridge, Lasso, and Elastic Net: NC State Statistical Learning Group (Fall 2014)

Teaching

All courses taught at NC State.

  • ST 312: Intro to Statistics II (Spring 2017, Spring 2015)
  • ST 311: Intro to Statistics I (Fall 2016, Fall 2014)
  • ST 350: Business Statistics (Fall 2012)
  • Mentor for Summer Institute in Biostatistics (Summer 2014)