I've been only for 2-3 years ato google, butit felt like (Ads-team perspective) that protobuf is the building block in google. Some databases can hold as data as protobufs, and then convert these row oriented beasts into multi-million column databases with each protobuf leaf being separate column (!) such that analysts/linguists/statisticians and other scientists can lookup their data quickly (given some latency of minutes to hours).