Because implementing your system and running experiments with it can happen concurrently, it is important to keep track of which version of your code you used for which experiment. With a fast development cycle, that can get tricky.
After struggling with sharing Maven artifacts for longer than I want to admit, I finally set up a dedicated artifact repository for Opencraft.
Failing hard drives and general system unavailablity every other week made me migrate more than 30 software repositories to a managed service.
This week I had a lot of fun teaching the basics of cloud computing at restart.network, a start-up company that offers computer-science bootcamps to refugees, helping them get into the Dutch job-market.