HNSW is a graph-based ANN algorithm that combines navigable small worlds and hierarchy, enabling scalable and high-performance vector search. HNSW has advantages over other ANN approaches, such as KD-Trees and Locality-Sensitive Hashing (LSH), but it also has tradeoffs, including higher memory consumption and index construction overhead. To implement HNSW effectively, teams must find the right balance between accuracy and speed, tuning parameters like M and efConstruction, and using parallel index construction and dynamic search tuning. Redis offers built-in support for HNSW-based ANN search, simplifying implementation and enabling teams to hit the ground running with both. With its efficient in-memory vector storage, real-time speeds of search performance, and native support for clustering and scaling, Redis is an ideal product to work with when HNSW sounds like a good fit for your workloads.