About Jeff Geerling:

Here is some descrition on his youtube channel: " K8s, Ansible, Raspberry Pi, photography, tech, DIY, tools, etc. Most anything has the potential for showing up on this channel. I might focus on one thing someday, but it's more fun to do ALL THE THINGS!" 

 Product purchase link： 52Pi  Super6C 

Here is one of the interesting projects he has done, using the Super6C from 52Pi official to build his own mini cluster.