@molecularmusing For interning, another thing I sometimes do in addition to sharding is a fixed-size thread-local cache since sharding doesn't help with contention for hot strings that hit the same shard. Another useful trick is to use a tagged representation (e.g. you can store small strings inline via a tagged pointer), so you bypass the data structure entirely; how much this matters depends on the use case (e.g. it can help a lot for identifiers in a compiler).