I recently wrote https://github.com/ronomon/hash-table https://github.com/ronomon/hash-table for Node.js, which has a few more design tips listed in the Readme,

I recently wrote https://github.com/ronomon/hash-table https://github.com/ronomon/hash-table for Node.js, which has a few more design tips listed in the Readme, specifically around optimizing a cuckoo hash table by reducing cache misses.