Jim Hester

Also known as jimhester

Jim Hester is a software engineer who builds R tools for data science, among them the covr test-coverage package, the lintr code checker, glue, readr and cpp11. After starting in healthcare analytics at Explorys and joining the Bioconductor team at the Fred Hutchinson Cancer Research Center, he moved to RStudio in 2016 and worked on Hadley Wickham's tidyverse team. His 2018 rstudio::conf talk "You can make a package in 20 minutes" turned a simple R script into a package, and in 2019 he was one of 24 authors of "Welcome to the Tidyverse". He presented cpp11 in 2020 and announced readr 2.0.0 in 2021, whose parsing engine is built on vroom. At Netflix, he is a Senior Software Engineer who builds infrastructure and supports the R community.

Now at: Netflix
Links: Website, X, LinkedIn and GitHub

Timeline

2013–2015

Explorys and the Bioconductor team

He works as a data scientist at Explorys from 2013, developing predictive models and classification methods that measure the quality of patient care. In 2015, he joins the Bioconductor team at the Fred Hutchinson Cancer Research Center in Seattle, where he first works on SummarizedExperiment.
2014–2016

The covr test-coverage package

In December 2014, he starts writing covr, an R package that aims to bring test coverage to the R ecosystem. He also writes lintr, which checks R code for style, syntax errors and possible semantic issues. In his 2016 RStudio webinar, he reports well over 1,500 packages using covr through two coverage services.
2016–2021

Tidyverse team at RStudio

He joins RStudio in 2016 as a software engineer on Hadley Wickham's tidyverse team, maintaining and improving open source R packages. He is the author and maintainer of packages including covr, devtools, glue and readr, and he stays until 2021.
2018

A package in 20 minutes

In 2018, he gives the rstudio::conf talk "You can make a package in 20 minutes" in San Diego, which takes a simple R script to a package with documentation, README, examples and tests using the devtools and usethis packages.
November 2019

Welcome to the Tidyverse

In November 2019, he is one of 24 authors of the Journal of Open Source Software paper "Welcome to the Tidyverse". The paper describes the tidyverse as a collection of R packages that share a design philosophy, grammar and data structures.
2020

The cpp11 package

In 2020, he presents cpp11, a header-only R package that helps developers handle R objects with C++ code, with goals and syntax similar to Rcpp. His talk "cpp11 - welding R and C++" takes place in November 2020.
July 2021

readr 2.0.0 and vroom

In July 2021, he announces readr 2.0.0 on the tidyverse blog. The major release brings a second-edition parsing and writing engine built on the vroom package, with lazy reading and multi-threading.
As of October 2026

Software engineer at Netflix

He is a Senior Software Engineer at Netflix, where he builds infrastructure and supports the R community.