There is a ripgrep "config file" (not mentioned in my previous comment), but there is only one and you have to set it via RIPGREP_CONFIG_PATH.

The things mentioned above are "ignore files," which are a sort of configuration for whitelisting and blacklisting files to search in a directory tree. And yes, you can splat them down into any directory, and if ripgrep enters that directory, it will read it and respect it. (Unless you tell it not to.)

If there are a lot of files with a lot of patterns, indeed, that can wind up taking a chunk of time not only building the matchers for each config file, but for actually matching them against every path. Sometimes it takes longer than not ignoring files at all! But if your ignore files are permitting ripgrep to skip GBs of data that GNU grep wouldn't otherwise skip, well, that's going to be a huge win no matter how you slice it.

ripgrep does use multi-threading as well, and it makes sure every ignore file is parsed and built only once. All other threads can then share the one single matcher.