Add Status, Pharmacist Worklists, and Digests to Prior Authorization

Scenario

Healthcare providers submit Prior Authorization (PA) requests to insurance payers to approve specific medications or procedures before treatment. Payer responses are notoriously asynchronous, arriving via webhooks, polling APIs, or manual clearinghouse updates over hours or weeks.

Your task is to design the core backend services for a health-tech platform that manages prior authorizations for pharmacy teams. The system must support real-time status visibility, an actionable worklist for clinical pharmacists, and reliable daily digest emails.

Requirements

Functional Requirements

• Status Tracking & Ingestion: Ingest asynchronous payer status updates (e.g., Approved, Denied, Additional Information Required, Expired). Expose APIs for clinics to query the current status and full history of any PA.
• Pharmacist Worklist: Provide a dynamic, filterable queue of PAs requiring pharmacist review (e.g., denials needing appeals, urgent requests close to SLA expiration). Pharmacists should be able to claim, update, and resolve work items concurrently without collision.
• Daily Digests: Generate and deliver personalized daily summary emails to clinic staff and pharmacists detailing overnight status changes, pending actions, and upcoming deadlines.

Non-Functional Requirements & Scale

• Scale: 100,000 active PAs at any time; 500,000 status events ingested per day; 25,000 daily digest recipients across different time zones.
• Consistency & Durability: Medical state transitions must be strictly ordered, durable, and auditable. Duplicate payer webhooks must be handled idempotently.
• Delivery Guarantees: Digest emails must follow at-least-once delivery semantics without spamming users upon retry failures.
• Latency: Worklist queries and status lookups should return within 200 ms at p95.

What to Cover

• High-Level Architecture: Core services, event flow from payer ingestion to pharmacist UI and email delivery.
• Data Model: Storage strategy for PA states, state change audit logs, worklist claims/locks, and digest tracking.
• Worklist Engine: How the worklist is indexed, filtered, and safely locked for concurrent pharmacist reviews.
• Digest Pipeline: Scheduling, batching, and failure handling for sending time-zone-aware notification digests.