ACME-1009: Spike for Authentication Service reliability improvement 09

Date: 2025-10-08 Type: Spike Priority: P1 Service: Authentication Service Owner: Identity Platform GitHub References: GH-1009, GH-1010 API References: API-AUTHENTICATION-01, API-AUTHENTICATION-02, API-AUTHENTICATION-03, API-AUTHENTICATION-04

Business Context

Acme Commerce depends on the Authentication Service to protect customer trust during high-volume shopping periods. This ticket captures engineering work needed after operational reviews found risk from background job lag after batch import exceeded expected cardinality.

Scope

• Review service contract behavior against API-AUTHENTICATION-02.
• Update dashboards and alerts owned by Identity Platform.
• Coordinate rollout with the teams that operate Authentication Service, Checkout Service, Billing Service, Inventory Service, and Notification Service.
• Link implementation work to GitHub items GH-1009, GH-1010.

Definition of Done

• Tests cover nominal, timeout, replay, and malformed payload scenarios.
• Runbook steps are updated and validated in staging.
• Incident review owners can cite this ticket as remediation evidence.