I'm not sure if this is true of modern Google. Certainly there are a ton of custom things around, but it also seems like in the last 5 years there has been a hu

I'm not sure if this is true of modern Google. Certainly there are a ton of custom things around, but it also seems like in the last 5 years there has been a huge push towards not re-inventing more databases/etc, and normalising everything onto a few core technologies. A good example is Spanner, many products have been moved off other home-grown systems onto Spanner, basically to reduce complexity and cost. Sure Spanner is a Google technology, but at least it's one, instead of having all sorts of different esoteric systems, and Spanner is just one example, this is happening in a number of different domains.