Now you can have screeching fast FPGA to PC communication over PCIe gen4x4 with Enjoy Digital's LiteX and a 500$ Alinx Artix Ultrascale+ board.
The Impact of Micro-Optimizations at Google Scale
Rick Altherr walks through the financial impact of optimization at Google scale, and provides anecdotes such as finding a CPU scheduler bug impacting search auto-complete, and allocating reserved PCIe pins for USB to expansion cards.