I read this when it came out and having written similar things for searchcode.com (back when it was a spanning code search engine), and while interesting I have questions about,

    We routinely see rg invocations that take more than 15 seconds

The only way that works is if you are running it over repos 100-200 gigabytes in size, or they are sitting on a spinning rust HDD, OR its matching so many lines that the print is the dominant part of the runtime, and its still over a very large codebase.

Now I totally believe codebases like this exist, but surely they aren't that common? I could understand this is for a single customer though!

Where this does fall down though is having to maintain that index. That's actually why when I was working on my own local code search tool boyter/cs on github I also just brute forced it. No index no problems, and with desktop CPU's coming out with 200mb of cache these days it seems increasingly like a winning approach.