Shopify webhooks are HTTP POST requests fired on store events: orders, inventory updates, checkouts, customers. By default, your endpoint handles them synchronously. That works until traffic spikes. The async pattern: Shopify fires webhook → Receiver validates HMAC, pushes to queue, returns 200 → Worker pulls job, runs business logic, marks complete Your endpoint responds in milliseconds. Your worker takes as long as it needs. The two things that actually trip people up in production: Idempotency. Shopify retries on failure. If your worker processes a duplicate orders/paid , you might charge a customer twice. Fix: check the webhook ID in Redis before processing. Skip if seen. Simple. Dead letter queues. Jobs that fail all retries need somewhere to go. Log them, alert on them, reprocess them manually. Without a DLQ, failed jobs vanish and you find out from a merchant complaint. Stack recommendations: BullMQ + Redis for Node.js, Laravel Queues for PHP, Celery for Python, SQS + Lambda for AWS-native.…