It has sqlite performances, which is the fastest you can get with Pareto effort.
Being sqlite backed, it's really fast and threadsafe, the cache is shared safely between all threads or processes.
It's a very mature library, too, nice and polished, I've never once experienced a bug with it.
Thread safety is a big issue with ours, we'll run into issues when two different processes attempt to write to the same location, or we'll get a bad read. This is a better solution for large scale workloads.
Ours is more meant for single-process scripts like an LLM workflow.