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Glossary

Who this is for

Developers, operators, evaluators, and reviewers who need shared RecSys terms without reading the old archived docs.

What you will get

  • A compact vocabulary for current canonical docs.
  • Terms that affect integration, operations, evaluation, and commercial review.
  • Pointers to the pages that own deeper procedures.

Terms

Term Meaning
Artifact Immutable, versioned output from offline computation, such as popularity or co-occurrence data.
Artifact mode Service mode where recommendation signals are loaded from a current manifest and artifact blobs.
Assignment Experiment membership event containing experiment ID, variant, request ID, and user identifier.
Backfill Reprocessing historical windows to rebuild canonical data or artifacts.
Candidate Item considered for ranking before final ordering and filtering.
Config version ETag for the active tenant config document.
Current manifest Mutable manifest path that tells the service which artifact URIs are live for a tenant and surface.
DB-only mode Service mode where signals are read from database-backed stores rather than published artifacts.
Exposure Event recording what recommendations were shown for one request.
Join rate Share of evaluation events that can be joined through stable identifiers, especially request_id.
Manifest JSON document mapping artifact types to artifact URIs for a tenant and surface.
Outcome Event recording what the user did after an exposure, such as click or conversion.
Ranking Scoring and ordering candidates into the final top-K response.
Request ID Correlation key used across recommendation responses, exposure logs, outcomes, and incidents.
Rules version ETag for the active tenant rules document.
Segment Cohort or slice label, with default used when no narrower segment is supplied.
Surface Product location where recommendations are shown, such as home, product_detail, or cart.
Tenant Organization or customer boundary for config, data, and authorization.

Example context

{
  "tenant": "demo",
  "surface": "home",
  "segment": "default",
  "request_id": "req_123",
  "config_version": "W/\"config-etag\"",
  "rules_version": "W/\"rules-etag\""
}