Individual skill
marketplace-recsys-feature-engineering
Feature engineering for marketplace recommenders — what to extract from raw marketplace assets (listing photos, owner-entered listing metadata, sitter wizard responses) to power item-to-item (similar listings), user-to-item (homefeed ranking), or user-to-user (mutual-fit matching) recommenders. Covers asset auditing, first-principles feature decomposition, vision-feature extraction (CLIP, room-type, amenities, aesthetics), listing text and metadata encoding, sitter wizard design, derived-composition patterns for i2i / u2i / u2u (ANN shelves, two-tower, mutual-fit), feature quality governance (training-serving parity, drift, PII), and incremental value proof (ablation A/B, kill reviews, feature-free baseline). Trigger even when the user does not explicitly say "feature engineering" but is asking how to get more signal out of listing photos, listing metadata, or the sitter onboarding wizard, or how to improve i2i / u2i / u2u quality without blindly ingesting a new model.
skills/.experimental/marketplace-recsys-feature-engineering/SKILL.md
Source commit cf93c57cac89d6fc3e4194686000411567f5caf3
What was checked
- Matches the observed repository HEAD
- Yes
- Scanner rules are current
- No
- Repository scan complete
- No
- Skill scan complete
- No
- Observed behavior
- Not checked yet
- Last checked
- Nov 5, 2026
These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.
Install this skill
Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.
An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.
Repository context
- Repository stars (not skill ratings)
- 222
- Repository last updated
- Aug 15, 2026
- License
- MIT
Observed agent integration: codex
- engineering Derived category
- design Derived category
Files and excerpt
File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.
Browse files
AGENTS.mddoc · 17,391 bytesREADME.mddoc · 7,057 bytesSKILL.mdcore · 14,393 bytesSKILL.mdcore · 14,393 bytesSKILL.mdcore · 14,393 bytesassets/templates/_template.mddoc · 1,233 bytesgotchas.mddoc · 661 bytesmetadata.jsonasset · 4,254 bytesreferences/_sections.mddoc · 4,081 bytesreferences/audit-measure-coverage-before-modelling.mddoc · 2,038 bytesreferences/audit-quantify-freshness-per-asset.mddoc · 2,077 bytesreferences/audit-sample-every-asset-type-end-to-end.mddoc · 2,048 bytesreferences/audit-separate-raw-assets-from-derived-features.mddoc · 1,962 bytesreferences/audit-verify-rights-and-privacy-before-extraction.mddoc · 2,020 bytesreferences/derive-cache-user-embedding-with-short-ttl.mddoc · 2,186 bytesreferences/derive-decompose-affinity-into-interpretable-subscores.mddoc · 2,270 bytesreferences/derive-fuse-modalities-before-item-similarity.mddoc · 2,219 bytesreferences/derive-precompute-i2i-nearest-neighbours-offline.mddoc · 2,190 bytesreferences/derive-score-u2u-as-symmetric-mutual-fit.mddoc · 2,179 bytesreferences/derive-use-two-tower-for-user-item-affinity.mddoc · 2,705 bytesreferences/firstp-ask-what-signal-a-human-uses.mddoc · 2,204 bytesreferences/firstp-kill-features-a-popularity-baseline-already-captures.mddoc · 2,190 bytesreferences/firstp-prefer-directly-observed-over-learned.mddoc · 2,023 bytesreferences/firstp-reject-features-you-cannot-serve-at-inference.mddoc · 2,315 bytesreferences/firstp-start-from-the-decision-not-the-algorithm.mddoc · 2,466 bytesreferences/firstp-tie-every-feature-to-a-specific-solution.mddoc · 1,860 bytesreferences/listing-declare-categorical-fields-for-bounded-vocabularies.mddoc · 2,494 bytesreferences/listing-embed-description-with-pretrained-sentence-encoder.mddoc · 1,990 bytesreferences/listing-encode-pet-requirements-as-structured-triples.mddoc · 2,169 bytesreferences/listing-extract-stay-duration-shape-not-just-length.mddoc · 2,020 bytesreferences/listing-hash-geo-to-hierarchies-not-raw-lat-lon.mddoc · 1,828 bytesreferences/listing-multi-hot-encode-amenity-lists.mddoc · 2,192 bytesreferences/playbooks/discovering.mddoc · 13,308 bytesreferences/prove-dedicate-random-exploration-slice-to-new-features.mddoc · 2,046 bytesreferences/prove-kill-features-that-dont-earn-maintenance.mddoc · 2,173 bytesreferences/prove-measure-lift-against-feature-ablated-variant.mddoc · 1,976 bytesreferences/prove-retain-feature-free-baseline-permanently.mddoc · 2,050 bytesreferences/prove-ship-one-feature-at-a-time.mddoc · 2,065 bytesreferences/quality-freeze-feature-schemas-per-model-version.mddoc · 2,351 bytesreferences/quality-gate-features-on-coverage-and-drift.mddoc · 2,559 bytesreferences/quality-scrub-pii-before-features-leave-secure-zone.mddoc · 2,190 bytesreferences/quality-serve-training-and-inference-from-one-store.mddoc · 2,526 bytesreferences/quality-version-feature-definitions-in-one-registry.mddoc · 2,281 bytesreferences/vision-detect-room-types-before-detecting-amenities.mddoc · 2,209 bytesreferences/vision-extract-per-object-counts-not-just-presence.mddoc · 2,159 bytesreferences/vision-fine-tune-on-your-domain-when-clip-underperforms.mddoc · 2,243 bytesreferences/vision-pool-embeddings-across-a-listings-photo-set.mddoc · 1,977 bytesreferences/vision-quantify-image-quality-separately-from-content.mddoc · 2,093 bytesreferences/vision-use-clip-for-zero-shot-listing-embeddings.mddoc · 2,024 bytesreferences/wizard-capture-experience-as-counts-and-dates.mddoc · 2,521 bytesreferences/wizard-make-skips-genuine-and-log-them.mddoc · 2,245 bytesreferences/wizard-order-questions-by-information-gain.mddoc · 2,259 bytesreferences/wizard-prefer-multiple-choice-over-free-text.mddoc · 2,316 bytesreferences/wizard-separate-hard-constraints-from-soft-preferences.mddoc · 2,382 bytes
Read excerpt
# Marketplace Engineering Recsys Feature Engineering Best Practices
Comprehensive first-principles guide for deriving usable recommender features from the raw assets of a two-sided trust marketplace — listing photos, owner-supplied listing metadata, and sitter wizard responses — for item-to-item, user-to-item, and user-to-user solutions. Contains 44 rules across 8 categories ordered by cascade impact on the feature-engineering lifecycle, plus one playbook that composes the rules into an end-to-end feature discovery workflow.
This skill is the **upstream precursor** to `marketplace-personalisation` (AWS Personalize) and `marketplace-search-recsys-planning` (OpenSearch retrieval). Those skills treat features as inputs they already have; this skill is about deciding what features to *build* from the raw assets, which decisions they serve, and how to prove each one is worth its maintenance cost.
## When to Apply
Reference this skill when:
- Planning what to extract from listing photos, descriptions, or amenity lists to power i2i similarity or u2i ranking
- Designing or revising the sitter onboarding wizard with recsys features as the primary output
- Deciding whether to build a vision embedding pipeline, a text encoder, or neither — and in what order
- Composing existing base features into item-to-item, user-to-item, or user-to-user scoring
- Auditing an existing feature store for coverage, drift, PII, duplication, or orphan features