Early Binding

What is Early Binding?

Early binding commits certain decisions before ranking—often at index time or pre-filter retrieval. Typical examples are ACL/security trimming, region/assortment gating, hard filters (in-stock/price bounds), or precomputed features (synonyms expansions, normalized attributes).

How It Works (quick)

• Index time: Store canonical attributes, ACL tokens, locale flags, normalized units; optionally pre-expand synonyms.
• Query time (pre-filter): Apply hard constraints first (stock, region, age-gated) → retrieve candidates → then rank.
• Caching: Because constraints are baked in or stable, caches hit more often and latency drops.

Why It Matters in E-commerce

• No leaks: Restricted SKUs/prices never reach ranking or snippets.
• Speed: Smaller candidate sets → faster ranking and UI.
• Signal quality: Ranking learns from valid items only (less noise).

Best Practices

• Security first: Index-time ACL tokens; deny before retrieve.
• Hard vs soft: Keep hard filters (stock/region/visibility) early; treat boosts/preferences later.
• Locale & units: Normalize currencies/sizes at index time.
• Synonyms strategy: Prefer late binding for context-sensitive synonyms; only pre-expand safe ones.
• Audit & logs: Record what was filtered early; monitor false negatives.

Challenges

• Over-filtering: Too-aggressive gates reduce recall.
• Reindex cost: Index-time mistakes require reprocessing.
• Context loss: Pre-expanded synonyms can add noise if meaning changes by query.

Examples

• B2B catalog: index ACL for contract pricing; non-entitled users never retrieve those SKUs.
• Region gating: only localizable, in-market items retrieved for a country store view.
• Stock gating: out-of-stock variants excluded before ranking.

Summary

Early binding applies non-negotiable constraints up front, protecting privacy, speed, and quality. Keep it for hard rules; leave preferences and context to later stages.