First let me say thank you for your work on R packages, you&#x27;ve helped a lot of people accomplish some great things!<p>Unfortunately I can&#x27;t go into specific details without potentially divulging proprietary information, but broadly most of the issues I&#x27;ve seen in production with R are corner cases involving multithreading with large amounts of allocated RAM (over 100GB), and corner cases involving the data.table package. I&#x27;ve also seen packages that update and break backwards compatibility, although that&#x27;s less of an issue. The biggest concern we have with R, however, is that the documentation and coding practices for most R packages make small bug fixes difficult without having extensive knowledge of the package code. This is not always true, but it&#x27;s true enough of the time that we can&#x27;t afford to maintain much production R code.