SadServers - A Playground for SREs, Admins And Devops Engineers

 SadServers is a playground where users can test their Linux troubleshooting skills on real Linux servers. Besides sharpening your troubleshooting skills, it is also suitable for practicing for SRE/DevOps interviews.

Others call it the "LeetCode for Linux". As LeetCode, there's challenges classified under difficulty level, a collection of scenarios, a description of what’s wrong and a test to check if the issue has been solved, within an allocated time length. After that time the VM is terminated.

https://www.i-programmer.info/news/80-java/15914-sadservers-a-playground-for-sres-admins-and-devops-engineers.html