Although I use R extensively in my work, samples can't be shared because of non-disclosure agreements with my clients. For this reason, I'm starting to build a portfolio of samples of my own work with R for data analysis and other tasks. Since COVID-19 is in the news now and I have experience with clinicaltrials.gov from my work with a biotech startup ( www.biostreamtech.com ), it seemed like a good way to start. The source code can be found at: https://github.com/davesides/covid_19_clinical_trials Some techniques used daily include: select to remove, order, rename columns mutate to add columns or modify values in columns filter to eliminate rows from a data frame arrange to order rows in a data frame group_by and summarize to pivot replace_na to replace NA with (typically) zeros read_tsv (csv, etc.) to read delimited files packages readxl and writexl to read and write Excel files Many more examples to come, but I wanted to post something as a starting point.