Redefining Technology

Artificial Intelligence

Maximizing Product Discovery in E-Commerce Using LLM for E-Commerce Technologies

LLM-powered product discovery replaces keyword matching with meaning: embedding models map queries and products into a shared semantic space, so "warm jacket for rainy commutes" returns the right parka instead of zero results. The stakes are measured: search abandonment costs US retailers $234 billion a year (Google Cloud), and 35% of Amazon purchases come from algorithmic recommendations (McKinsey).

What is LLM-powered product discovery?

LLM-powered product discovery is the use of large language models and embedding models to run every surface where shoppers find products — site search, recommendations, category navigation, and conversational assistants — on meaning rather than string matching. Each query and each product is represented as a vector that encodes intent, so "quiet vacuum for a small flat" retrieves compact, low-decibel machines even when no product title contains those words.

The commercial case rests on how badly the incumbent approach fails. Site search is the highest-intent surface a store owns, and it is exactly where keyword engines break: misspellings, paraphrases, and problem-shaped queries return zero or irrelevant results, and the shopper leaves — usually for a marketplace that answers the same query correctly.

Recommendations carry the other half of discovery, and the ceiling is documented. The benchmark every retailer measures against is Amazon, where algorithmic suggestion is not a sidebar widget but a primary sales channel.

Keyword search matches the literal tokens of a query against indexed product text; embedding search compares dense vectors that encode what the query and the product mean. The difference is invisible on "iphone 15 case" and decisive on "gift for a coffee-obsessed dad under $50" — the long-tail, natural-language queries that carry the most purchase intent and produce the most zero-result pages.

Keyword search vs embedding search vs hybrid retrieval
CriteriaKeyword (lexical)Embedding (semantic)Hybrid
Matches onLiteral tokens, stems, synonym listsMeaning encoded as vectorsBoth, merged and reranked
Long-tail natural-language queriesZero or irrelevant resultsResolves intent to productsResolves intent to products
Exact SKU, brand, model lookupsPreciseCan blur near-duplicatesPrecise — lexical path wins
Misspellings and paraphraseNeeds hand-built dictionariesHandled by the modelHandled by the model
Merchandising controlMature: boosts, pins, rulesImmature on its ownKeeps the existing rule stack
Cost to addAlready installedEmbedding pipeline + vector indexIncremental on the current engine
Where site search breaks, by query type

Baymard Institute benchmarks large e-commerce sites on each type of search query a shopper can type. Exact lookups are close to solved; the intent-shaped queries — use case, compatibility, symptom — fail on three to five times as many sites.

Source: Baymard Institute, E-Commerce Search UX benchmark (opens in a new tab)

View the data
ItemShare of benchmarked sites with issuesNote
Exact SKU or model12%"Nike Air Zoom Pegasus 40" — the shopper already knows the product
Product type20%"running shoes" — the category term the catalog already uses
Symptom37%"knee pain when running" — the problem, not the product
Feature39%"waterproof running shoes" — an attribute that may not be a facet
Use case43%"shoes for standing all day" — the query semantic retrieval is built for
Non-product question66%"return policy" — answerable only from content outside the catalog

That benchmark is the business case in one line: lexical retrieval is close to solved for the queries shoppers type when they already know the product, and weakest on the queries they type when they do not. Discovery — as opposed to re-finding — lives almost entirely in the second group, which is also where basket size grows, because a shopper who describes a situation rather than a SKU is open to being shown the right answer.

Hybrid retrieval is the deployment answer, not a compromise. Lexical retrieval keeps part numbers, brand names, and merchandising rules exact; vector retrieval catches everything phrased like a human; a reranking model orders the merged candidates. Relevance is the whole game — 88% of consumers call a good search function very important or essential, and only 12% say they get exactly what they searched for every time (opens in a new tab) (Google Cloud & The Harris Poll), and the reranker is the component that closes that gap.

How to add LLM-powered discovery to an existing store

A production rollout is a sequencing problem: enrich the data before indexing it, index before tuning, tune before testing, and hold every step against a baseline recorded up front. Scoped to one category and one surface, the sequence below fits the 90-day window we scope first production releases to.

The target architecture is smaller than most replatform proposals suggest. One query fans out to two retrievers reading the same enriched catalog, and the merged candidates pass a reranker before anything reaches the shopper. Nothing is thrown away: the lexical engine running the store today becomes one of the two paths.

How a hybrid retrieval stack answers one shopper query

The enriched catalog feeds both indexes, so semantic and lexical retrieval argue over the same facts. The reranker is the single place where relevance, stock, and merchandising rules are reconciled — and the same ranked output serves search results, recommendation slots, and a grounded assistant.

Read this diagram as a list
  1. Shopper query — "warm jacket for rain"
  2. Enriched catalog — attributes · use-case tags
  3. Lexical index — tokens · SKU · brand
  4. Vector index — embedding neighbours
  5. Merge and rerank — one ordered candidate set
  6. Discovery surfaces — search · recs · assistant
  1. Baseline the discovery funnel (weeks 1–2)

    Instrument and record four numbers before touching anything: zero-result rate, search exit rate, search-to-add-to-cart conversion, and revenue per search session. These are the figures the pilot is judged against; without them, "better search" stays an opinion.

  2. Enrich the catalog (weeks 2–5)

    Run the catalog through an LLM extraction pass: normalise attributes into one taxonomy, fill missing facet values from descriptions and supplier feeds, and tag each SKU with the use cases shoppers actually search. Generation stays grounded in the source record and passes a review queue before anything publishes.

  3. Stand up hybrid retrieval (weeks 4–7)

    Embed the enriched catalog into a vector index alongside the existing lexical engine — Elasticsearch, OpenSearch, and most commerce platforms now hold both. Route queries down both paths and merge candidates; do not switch the lexical path off.

  4. Tune relevance on real query logs (weeks 6–9)

    Replay the store's top 1,000 queries plus a sample of zero-result queries through the new stack, judge the results against a rated set built by merchandisers, and tune the reranker and merge weights. The zero-result sample is where semantic retrieval shows its largest and fastest wins.

  5. A/B test against the baseline (weeks 9–12)

    Ship the hybrid stack to a traffic split and read the four baseline metrics. Promote only what moves them; a relevance improvement that does not move add-to-cart is a tuning target, not a victory.

  6. Extend to recommendations and conversation (week 12+)

    The same embeddings power "similar products", "complete the look", and a grounded conversational assistant — each is one more retrieval surface over the enriched catalog, added incrementally, never a rebuild.

Product discovery, quantified

$234B

lost by US retailers to search abandonment every year

Source: Google Cloud & The Harris Poll

43%

of benchmarked sites mishandle use-case search queries

Source: Baymard Institute

35%

of Amazon purchases come from algorithmic recommendations

Source: McKinsey & Company

How does LLM catalog enrichment work?

LLM catalog enrichment is an extraction-and-normalisation pass in which a language model reads each product's existing text — titles, descriptions, supplier feeds, spec sheets — and writes back the structured data discovery depends on: consistent attributes, complete facet values, and use-case tags. It attacks the root cause of bad search results, which is thin and inconsistent product data, not the ranking algorithm.

  • Attribute extraction The model pulls material, fit, capacity, compatibility, and dimensions out of free-text descriptions into typed fields, so filters and facets stop silently excluding half the catalog.
  • Taxonomy normalisation "Crimson", "wine", and "burgundy" collapse into one filterable value; sizes, units, and category assignments align across suppliers who each shipped their own schema.
  • Use-case tagging SKUs get tagged with the situations shoppers search — "office chair for back pain", "gift under $50" — which is exactly the vocabulary embeddings match against.
  • Query-aware copy Descriptions are rewritten to answer what shoppers ask, in brand voice, grounded in the source record so no claim appears that the underlying data cannot support.

The guardrail matters as much as the generation. Every enrichment pipeline we ship gates output through a human review queue with per-category approval rules, and tracks review pass rate — the share of generated fields approved without edits — as its quality metric. It is the same grounded-drafting, human-approval pattern our LLM-based outreach systems use before any message reaches a customer.

Enrichment compounds. The same structured attributes improve search filters, recommendation quality, shopping-ad feeds, and the grounding corpus a conversational assistant answers from — one data investment lifting four surfaces, which is why it sits second in the rollout sequence, directly after the baseline.

Which discovery surface should you start with?

Start with site search on your highest-volume category: it carries the highest purchase intent, its baseline can be recorded in two weeks, and everything it forces you to build — the enriched catalog, the embeddings, the vector index, the reranker — is reused unchanged by recommendations and by any assistant added later. Recommendations and conversation are downstream of the same work, not alternatives to it.

Which surface to build first

Ready to buyShopper intent on the surfaceBrowsing

Enrich, then search

  • High intent, but the data cannot answer
  • Two to four weeks of LLM extraction first
  • Ship search the moment attributes land

Start here: site search

  • Highest-intent traffic in the store
  • Zero-result rate is measurable in two weeks
  • Builds the index every later surface reuses

Not yet: assistants

  • A chat assistant on thin data stalls or invents
  • Needs both enrichment and retrieval in place

Second wave: recommendations

  • Similar items, complete-the-look, bundles
  • Reuses the embeddings already paid for
  • Judged on attach rate, not relevance scores

Thin, inconsistentCatalog dataStructured, enriched

Pick the surface by shopper intent and by how much the catalog already describes each product. Everything in the left column is a data problem wearing a retrieval costume — enrich first, and the other three quadrants get cheaper.

The arithmetic picks the category, not the enthusiasm. A store handling 2 million site searches a year at a 15% zero-result rate sends 300,000 sessions to a dead end. Recovering half of those at a 3% search-to-order conversion and a £70 average order value is £315,000 of orders that already had intent behind them. Run the same three lines per category and start with the biggest number — then re-run it after the pilot with measured figures instead of assumed ones.

300,000

dead-end searches a year at a 15% zero-result rate on 2M searches

£315k

recovered by halving that rate at 3% conversion and a £70 order value

90 days

to a measured pilot on one category and one surface

What is conversational product discovery?

Conversational product discovery is a storefront or messaging assistant that narrows a shopper from vague intent to a shortlist through dialogue — asking clarifying questions, applying constraints, and answering product questions from catalog data. It replaces the query-refine-scroll loop with a guided exchange, which is why assistants measurably compress product discovery time.

The behavioural shift is not speculative: shoppers are moving query volume from search boxes to assistants, and analysts priced the move in before it happened.

Production-grade means grounded. The assistant retrieves from the enriched catalog and answers only from what it retrieved, with confidence thresholds, a hand-off path to human support, and full conversation logging. Architecturally it is retrieval-augmented generation over the same vector index the search stack already built — a conversational and generative AI system in the standard pattern, not a raw model behind a text box.

Discovery also extends past the storefront. The same grounded-generation pattern that answers an on-site question can open a conversation: outreach systems draft recommendation and re-engagement messages from CRM and catalog data, gate them behind review queues, and measure replies per segment. That is how a discovery layer becomes a revenue channel on both the inbound and outbound sides of the funnel.

Where LLM product discovery fails

LLM discovery fails in five predictable places: thin catalog data, exact-match regressions, relevance judged by opinion, merchandising rules lost in the rerank, and latency and cost per query. None of them show up in a vendor demo on a clean sample catalog; all five show up in week one of production traffic, and all five are cheaper to find in a scoped pilot than after a replatform.

  • Thin product data Embeddings encode whatever text exists. Given a three-word title, the model clusters products by brand rather than by purpose, and semantic search returns confident nonsense. Enrichment comes before indexing — never after, when the index has already trained the merchandising team to distrust it.
  • Exact-match regressions Pure vector search blurs near-identical SKUs, so a shopper typing a model number gets the product family instead of the item. This is the single most common reason a semantic launch is rolled back, and keeping the lexical path is the whole fix.
  • Relevance judged by opinion Without a rated judgement set — 300 to 500 query-product pairs scored by people who know the catalog — tuning becomes an argument between merchandisers and engineers. Build the set before touching the reranker, and re-rate it quarterly as the catalog turns over.
  • Merchandising lost in the rerank Margin, stock, campaign, and compliance rules have to survive the merge. A reranker optimised on relevance alone will cheerfully promote an out-of-stock item at the top of the page. Apply business rules after the model, as explicit constraints, not as prompt suggestions.
  • Latency and cost per query An embedding call plus a cross-encoder on every keystroke adds both milliseconds and cost. Embed the catalog once and cache it, embed the query once per submitted search rather than per character, and rerank only the top hundred candidates — a discovery layer that costs more than the margin it recovers is not a discovery layer.

There is a sixth failure mode that is organisational rather than technical: nobody owns relevance after launch. Catalogs turn over, seasons change the meaning of "warm", and new suppliers arrive with new schemas. Give one named person the weekly review of top queries, zero-result queries, and search conversion, and the system keeps earning; leave it unowned and it decays into the engine it replaced.

Key terms

Embedding
A numeric vector produced by a model that places text or images in a shared semantic space, so items with similar meaning sit close together. Product discovery uses embeddings to match a shopper's phrasing to products whose descriptions never contain those exact words.
Hybrid retrieval
A search architecture that runs a lexical index and a vector index over the same catalog and merges the two candidate sets before ranking. Lexical retrieval keeps SKU, brand, and model lookups exact; vector retrieval handles natural language and paraphrase.
Reranker
A second-stage model that reorders merged candidates by scoring each product against the full query rather than by index score. It is the one place where relevance, stock, margin, and merchandising rules are reconciled into a single order.
Zero-result rate
The share of on-site searches that return no products. It is the fastest-moving metric when semantic retrieval is added, and the one to record for at least two weeks before any change so that improvement can be measured rather than asserted.
Catalog enrichment
An LLM extraction pass that reads existing product text and writes back structured attributes, normalised taxonomy values, and use-case tags. One pass lifts search filters, recommendation quality, shopping-ad feeds, and the grounding data a conversational assistant answers from.
Judgement set
A rated list of query-product pairs, scored by people who know the catalog, used to measure whether a retrieval change actually improved relevance. It turns tuning from an argument into a measurement, and it is re-rated as the catalog turns over.

Frequently asked questions

The questions e-commerce, product, and engineering leaders ask before adding an LLM discovery layer.

What is the difference between semantic search and keyword search in e-commerce?

Keyword search matches the literal words of a query against indexed product text, so it fails when shoppers phrase intent differently from the catalog. Semantic search compares embedding vectors that encode meaning, so "shoes for standing all day" retrieves cushioned work sneakers no title mentions. Production systems run both: lexical retrieval for exact SKU and brand lookups, vector retrieval for natural language, and a reranker ordering the merged results.

Do I need to replace my existing e-commerce search engine?

No. The standard pattern is hybrid: keep the existing lexical engine for exact matches, add a vector index for semantic retrieval, and merge the two result sets with a reranking step. Elasticsearch, OpenSearch, and most commerce platforms now support vector fields natively, so the addition is an index and a retrieval path, not a replatform. Replace the engine only if it cannot hold a second index.

How long does it take to add LLM-powered product discovery?

A scoped pilot — one category, hybrid search plus enriched attributes, measured against a recorded baseline — fits inside 90 days, the first-production-release window we scope engagements to. Embedding and indexing a catalog takes days; most of the calendar goes to data cleanup, relevance tuning on real query logs, and the A/B test that proves the lift before rollout.

Should we start with search, recommendations, or a chat assistant?

Search, on your highest-volume category. It carries the highest purchase intent, its baseline can be recorded in two weeks, and the enriched catalog and vector index it forces you to build are exactly what recommendations and a grounded assistant run on afterwards. Starting with an assistant on an unenriched catalog produces fluent answers about products your data does not actually describe.

Can LLMs write product descriptions without making things up?

Yes, when generation is grounded and gated. The model is constrained to the source record — existing copy, supplier feeds, structured specs — instructed to output only claims present in that data, and every generated field passes a human review queue before publishing. Review pass rate then becomes the quality metric: rising approval-without-edits means the grounding works.

How do we prove the semantic results are actually better?

Build a judgement set before tuning: 300 to 500 query-product pairs drawn from your top and zero-result queries, rated by merchandisers who know the catalog. Tune against that set, then A/B test on the four baseline metrics. Relevance scores that rise while add-to-cart stays flat mean the judgement set does not reflect what shoppers buy — that is a tuning signal, not a victory.

Which metrics show that product discovery is improving?

Four move first: zero-result rate, search exit rate, search-to-add-to-cart conversion, and revenue per search session. Record all four for two weeks before changing anything, so every later claim of improvement is measured against that baseline. Recommendation surfaces add click-through and attach rate per placement; assistants add containment rate and hand-off rate.

Put an LLM discovery layer on your storefront

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