https://cloud.google.com/blog/products/gcp/google-shares-software-network-load-balancer-design-powering-gcp-networking
https://cloud.google.com/blog/products/networking/google-cloud-networking-in-depth-cloud-load-balancing-deconstructed
https://research.google.com/pubs/archive/44824.pdf
etc. for some higher level info
