Glossary · E-commerce ML

Product Embeddings

also: item embeddings · transformer embeddings

Definition

Product embeddings are dense vector representations of items in a learned semantic space, such that geometrically close items are similar in the behavioral or content sense. Transformer-based embeddings trained on session sequences capture nuanced substitute/complement relationships that simple collaborative filtering misses.

Early embeddings (word2vec adapted to item2vec) learned from co-occurrence. Modern transformer architectures (BERT4Rec, SASRec, Pinterest's PinnerSAGE) capture sequential intent — 'what did the user view next' — and produce embeddings where vector arithmetic reflects substitution and complement structure. Embeddings also enable zero/few-shot recommendation for cold-start items via content-derived vectors.

Essays on this concept