I use it for CI/CD on projects, but also for automating other tasks -- You can use Jenkins to wrap any arbitrary script with more higher-level logic and extensibility than a cron job.

For example, I use Jenkins to automate multiplatform builds for some side projects, to periodically ingest data into a database, perform cleanup jobs, etc.

Just set up a Tor proxy that I can connect to with one command from my PC, by connecting to the PI via SOCKs proxy, good times