Google talks a fair bit about their internal systems at this level of "descriptions but not code" - Bigtable, MapReduce, Spanner, Flume, Chubby, and more have been influential.
In fact, they do more than just talk: they often publish papers describing how they work. The open source community has since recreated a lot of them, which has proven useful to a lot of people (e.g. HBase, Hadoop, Apache Crunch, etc.)
