Price Sync Flow

Orchestration pipeline for global market synchronization, alert evaluation, and in-app notification delivery.

Sequence (current architecture)

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Alert Trigger Conditions

Condition	Evaluation Logic
PriceAbove	quote.CurrentPrice > rule.TargetValue
PriceBelow	quote.CurrentPrice < rule.TargetValue
PriceTargetReached	`
PercentDropFromCost	(costBasis - currentPrice) / costBasis * 100 >= rule.TargetValue
LowHoldingsCount	SUM(BuyQty) - SUM(SellQty) < rule.TargetValue

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Logic Highlights

Feature	Detail
Parallel I/O	SyncPricesJob uses Parallel.ForEachAsync to fetch quotes, significantly reducing latency.
Bulk Persistence	Uses AddRangeAsync for PriceHistories and Notifications to minimize EF Core overhead.
N+1 Avoidance	Fetches all relevant AlertRules in a single query using GetBySymbolsAsync.
Evaluator + Cooldown	IAlertRuleEvaluator applies rule logic and enforces a Redis cooldown key to prevent alert storms.
In-App Notification	Alert breaches write to the Notification table, then are pushed via SignalR (IAlertNotifier).
Single Transaction	All state changes (history, notifications, rule updates) are saved in one unit of work.
TriggerOnce	If rule.TriggerOnce = true, rule is disabled automatically after first breach.
User Isolation	LowHoldingsCount and PercentDropFromCost always filter by (UserId, TickerSymbol).

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Relationship to SQS (integration events)

SQS is used for event-driven evaluation paths that are separate from the scheduled SyncPricesJob:

• The API can publish an EventEnvelope to SQS (see POST /api/v1/events).
• The Worker polls SQS continuously (ProcessQueueJob) and routes known event types:
  • inventoryalert.pricing.price-drop.v1 → MarketPriceAlertHandler
  • inventoryalert.inventory.stock-low.v1 → LowHoldingsHandler
  • inventoryalert.news.sync-requested.v1 → enqueue NewsSyncJob