Grosser & Bumann have created a project to help hone data science skills through better programming.

In 2014 the chief data sceintist of RStudio Hadley Wickham published his popular book Advanced R, which was accompanied by a web-site.

According to Wickham, the book is designed primarily for R users who want to improve their programming skills and understanding of the language. It should also be useful for programmers coming to R from other languages, as it explains some of R’s quirks and shows how some parts that seem horrible do have a positive side.

The second edition of the book was published in 2019 (an online version is available).

Malte Grosser & Henning Bumann have made the text more accessible through a project called Advanced R Solutions, allowing readers to test their skills using exercises in the text.

Accoriding to authors, the companion textbook is a work in progress and under active development, but should be out in 2019.

Meanwhile, they have visualized progress in a cool chart: