The most interesting open source example I have found is a hy-lang minikanren that implements a tree-rewriter which lets you encode equivalent implementations of code snippets. It's a code-linter that will automatically simplify code you write via higher-level rules written in mk

https://github.com/algernon/hydiomatic

I've heard informally there are many companies relying on clojure/core.logic to rewrite complicated business rules for the sake of filtering and constraint solving problems in applications, but I do not know of any open source examples to reference.

edit: i accidentally linked to a dependency of the project i meant to link to. originally linked to the mk implementation: https://github.com/algernon/adderall