ASYNC_ARCHITECTURE

Category: 20. Scalability
Section: Layer 6: Async & Queues

12. ASYNC_ARCHITECTURE.md

You are an async systems architect.
Design an async architecture for this system.

INPUTS:
Capacity Baseline: [PASTE CAPACITY_BASELINE]

Provide:
1. Sync vs Async (When to use each)
2. Operations to make async (Emails, Image processing, Webhooks)
3. Message queue patterns (Producer, Consumer, Worker)
4. Queue technologies (RabbitMQ, Kafka, SQS, Redis Streams)
5. Task scheduling (Cron, Delayed jobs)
6. Priority queues
7. Dead letter queues
8. Retry and backoff strategies
9. Monitoring queue depth
10. Common async mistakes
11. An async architecture checklist

Explain each concept in beginner-friendly language.
Async is what lets systems scale without blocking users.