ARM server farm. There are four Banana Pi Servers in the rack on the left, and Raspberry Pi servers in the other two racks. The racks are resting on top of a PC that I’m using as a load balancer to distribute traffic to the servers.
On top of the pile there’s a large ethernet switch which the servers are connected to. All connections from this switch are on the server subnet.
The other switch gives access to the local network. The router right at the top is used by the servers to send email to the outside world.