01Model selection

A task-specific benchmark avoids choosing an encoder by reputation.

Two reproducible protocols separated textual search from image similarity. On public catalogues, FashionCLIP improved visual NDCG@10 by 7.9% on Amazon Berkeley Objects and 4.6% on H&M compared with CLIP. For semantic search, a dedicated text encoder remained stronger.

The decision was to preserve several specialized spaces until a hybrid benchmark could justify merging them. Because categories provide only a proxy for relevance, results were interpreted with explicit limitations and complemented by qualitative inspection.

02Pipeline

Incremental computation separates expensive inference from product strategy.

Each product field—name, description and image—has a fingerprint and a versioned representation. Only new or modified content is re-encoded. Removed products follow an explicit deletion rule, while image errors and optional fields use observable fallback strategies.

Embeddings are combined with configurable weights and normalized. Fusion strategy can therefore change without recomputing the entire catalogue. Separation by model and field also lets several versions coexist during migration.

03Serving & scale

The architecture makes retrieval trade-offs measurable.

ClickHouse, HNSW indexes and in-memory strategies were compared on relevance, latency and load behavior. FastAPI exposes the required operations, while orchestration, containerization and load testing make the path reproducible.

A GPU embedding service was also evaluated to saturation to separate hardware gains from batching and orchestration limits. Those measurements informed capacity planning instead of becoming a technology preference by default.

04Production

Output tests and monitoring extend the benchmark after deployment.

The multimodal pipeline is now in production. Operations monitor catalogue coverage, encoding failures, neighbour availability, latency and model versions. Migrations and metadata consistency receive functional checks because a query may technically succeed while still returning an incorrect ranking.

Experimental components stayed outside the critical path when they did not add enough value. Automatic segmentation, for example, introduced failures and cost without a sufficiently robust improvement for the first version. This decision reduces complexity while retaining an ablation protocol for future catalogues.