At rOpenSci, we encourage R package developers to take advantage of Continuous Integration services to automatically check the package on different platforms, with different versions of R. The rOpenSci dev guide dedicates chapter 2 to the topic of Continuous Integration Best Practices, and recommends a few common CI vendors, including Travis CI.
This is a companion discussion topic for the original entry at https://ropensci.org/technotes/2020/11/19/moving-away-travis/