None of Google's public source search engines (android, chromium, bazel) use Zoekt. They use Google's web indexing technology adapted for trigrams, which was mostly developed to support their massive internal monorepo, but exposed for a few of their major open source projects too.
You can index private repos with Sourcegraph, but it's a paid feature ($19/mo/user+).
> They use Google's web indexing technology adapted for trigrams, which was mostly developed to support their massive internal monorepo
Do you have a source for this? I would love to read more about it.
In the doc of the Zoekt repo, it says
> What does cs.bazel.build run on?
> Currently, it runs on a single Google Cloud VM with 16 vCPUs, 60G RAM and an attached physical SSD.
https://github.com/sourcegraph/zoekt/blob/main/doc/faq.md#wh...
so at least they were using Zoekt up until a certain point in the past.