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⚙️ Worker Jobs Optimization & Finnhub Quota Strategy

This document details the background worker job architecture in InventoryAlert.Worker, focusing on job consolidation, Finnhub free-tier API rate limiting, and zero-collision scheduling.

📊 Consolidated Job Catalog (6 Total Jobs)​

Job Class NameCRON ScheduleRole & Target EndpointKey Duty
SyncPricesJob*/15 * * * *Finnhub /quoteActive symbol fetch → PriceHistory insertion → AlertRule evaluation → Notification creation → SignalR push.
SyncStockFundamentalsJob10 6 * * */metric, /earnings, /recommendation, /insider-transactionsConsolidated daily sync for basic financials, quarterly earnings, analyst trends, and SEC insider trades for active symbols.
NewsSyncJob5 */2 * * *Finnhub /news & /company-newsConsolidated market + active company news batch sync to DynamoDB read models.
CleanupPriceHistoryJob20 2 * * *Postgres PriceHistoryPurges price history snapshots older than 1 year to keep DB storage lean.
KeepAliveJob*/10 * * * *http://127.0.0.1:8080/healthzSelf-pings health endpoint to guarantee 24/7 Render free-tier container uptime ($0 cost).
ProcessQueueJobContinuous PollerAWS SQS event-queueNative SQS listener, Redis deduplication (msg:processed:{id}), and integration event routing.

📈 Finnhub API Rate-Limiting Strategy​

  1. Free Tier Limit: 60 API requests/minute.
  2. Active Ticker Resolution (GetActiveSymbolsAsync): Background jobs do NOT scan all historic listings in the database. Instead, jobs fetch distinct symbols actively present in user WatchlistItems, Trades, or AlertRules.
  3. Throttling Delays: SyncStockFundamentalsJob enforces a 1,000ms delay between requests to ensure maximum throughput stays strictly below the 60 req/min limit.

🕒 Zero-Collision Staggered Schedule​

Jobs run on distinct minute marks to avoid concurrent API call collisions:

[Minute 00, 15, 30, 45] ➔ SyncPricesJob (Runs for ~50s)
[Minute 05]            ➔ NewsSyncJob (Runs every 2 hours at :05)
[Minute 10 (at 06:10)] ➔ SyncStockFundamentalsJob (Throttled 1s delay, runs ~3.3 mins)
[Minute 20 (at 02:20)] ➔ CleanupPriceHistoryJob (Runs ~2s)