The two major ones were a JWT package being deprecated, and then adding go mod which didn’t exist when I started. Then some smaller go vet issues.

I recently converted some Go code from 1.13 to 1.19, and the bulk of the work was replacing vendored dependencies with go modules and updating the CI/CD pipelines to properly cache said modules.

Changes I remember included updating ioutil.ReadFile() to be os.ReadFile(), and some other similar depreciations.

I've noticed over time that the various linters and vet-tools have become more strict about things that they didn't detect in the past.

But I tend to write code with reasonably high levels of coverage (in the 80-100% region) so running linters and test-cases has always been part of my approach to using go.