According to ” jurvetson“, this was Google’s very first production server — circa 1999. Here’s an interesting fact you might not have known: “the beta system used Duplo blocks for the chassis because generic brand plastic blocks were not rigid enough.” View full-sized picture here.
Each level has a couple of PC boards slammed in there, partially overlapping. This approach reflects a presumption of rapid obsolescence of cheap hardware, which would not need to be repaired. Several of the PCs never worked, and the system design optimized around multiple computer failures