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