SQS vs EventBridge
Compare queue-based asynchronous messaging with event bus routing in AWS.
Messaging
Amazon SQS
Amazon SQS is a queue service that stores messages for asynchronous consumption by workers. It is commonly used for buffering, retries, decoupling, and background task processing.
Messaging
Amazon EventBridge
Amazon EventBridge is an event bus service that routes events from sources to targets using rules and patterns. It is designed for event-driven integration across AWS services and applications.
Key Differences
SQS is a queue, while EventBridge is an event bus.
SQS stores work items for consumers to pull, while EventBridge routes events to matching targets automatically.
SQS is stronger for durable asynchronous worker processing, while EventBridge is stronger for event-driven integration and rule-based routing.
EventBridge supports routing patterns and event filtering, while SQS focuses on queue semantics and message consumption.
SQS is often used when processing control and buffering matter, while EventBridge is often used when integration between services matters.
The core distinction is queued work processing versus event routing.
When to Use
When to use SQS
Use SQS when you need durable asynchronous job processing, worker decoupling, retries, and controlled message consumption.
When to use EventBridge
Use EventBridge when you want to route events across services and applications based on rules and event patterns in an event-driven architecture.
Tradeoffs
SQS is excellent for queue-based processing, but less expressive for event routing across many systems.
EventBridge is excellent for event integration, but not a replacement for durable queue semantics in worker processing.
The better choice depends on whether the problem is routing events or processing queued work.
Common Mistakes
Using EventBridge as if it were a worker queue.
Using SQS when the architecture really needs flexible event routing across multiple targets.
Not separating event bus concepts from queue processing concepts.
Interview Tip
The short answer is: SQS is for queued work, EventBridge is for event routing.