7 questions found
What is Amazon EventBridge and what problem does it solve?
Beginner
Amazon EventBridge is a fully managed serverless event bus service that makes it easy to connect applications together using events, letting you route events from sources such as your own applications, AWS services, or third party software as a service providers to targets like Lambda functions, without needing to write custom integration code between every pair of systems.
aws events put-rule --name 'OrderPlacedRule' --event-pattern '{"source":["myapp.orders"]}'
Real-world example
An online retailer publishes an order placed event to EventBridge whenever a customer completes checkout, and multiple independent services, such as inventory, shipping, and email notifications, each react to that single event without being directly connected to one another.
Common follow-ups: What is the difference between EventBridge and SNS?;What are event buses and how many can an account have?
Amazon SNS (Simple Notification Service);Lambda & Serverless
What is an event pattern in EventBridge and how is it used?
Beginner
An event pattern is a JSON structure that describes the specific characteristics of events you want a rule to match, such as a particular event source, a specific detail type, or particular values within the event's data, and only events that match this pattern are forwarded to the targets configured for that rule, letting you precisely filter which events trigger which actions.
{
"source": ["aws.ec2"],
"detail-type": ["EC2 Instance State-change Notification"],
"detail": { "state": ["stopped"] }
}
Real-world example
An operations team creates an EventBridge rule with an event pattern that only matches EC2 instances entering a stopped state, triggering an automated notification only for that specific scenario rather than every possible EC2 event.
Common follow-ups: How specific can an event pattern be, such as matching numeric ranges?;What happens if no rule matches an incoming event?
Monitoring (CloudWatch);EC2 & Compute
How do EventBridge rules and targets work together to trigger actions?
Intermediate
A rule defines the event pattern or schedule that determines when it should fire, while a target defines what action should happen when the rule matches, such as invoking a Lambda function, sending a message to an SQS queue, or starting a Step Functions workflow, and a single rule can have multiple targets, meaning one matching event can trigger several different actions simultaneously.
aws events put-targets --rule 'OrderPlacedRule' --targets 'Id'='1','Arn'='arn:aws:lambda:us-east-1:123456789012:function:sendConfirmationEmail'
Real-world example
An order processing system configures a single EventBridge rule with three separate targets, so a single order placed event simultaneously triggers an inventory update, a shipping label creation, and a customer confirmation email.
Common follow-ups: What is the maximum number of targets a single rule can have?;What happens if one target fails while others succeed?
Lambda & Serverless;AWS Step Functions
How can EventBridge be used to schedule recurring tasks, and how does this compare to using cron directly?
Intermediate
EventBridge supports scheduled rules using either a rate expression, such as every five minutes, or a standard cron expression for more specific scheduling needs, letting you trigger a Lambda function or other target automatically on a recurring basis without needing to run and maintain your own dedicated scheduling server.
aws events put-rule --name 'DailyReportRule' --schedule-expression 'cron(0 9 * * ? *)'
Real-world example
A finance team schedules an EventBridge rule to trigger a Lambda function every morning at nine that generates and emails a daily sales report, entirely without provisioning any server to run that scheduled job.
Common follow-ups: What is the difference between rate expressions and cron expressions in EventBridge?;How does EventBridge Scheduler differ from scheduled rules?
Lambda & Serverless;AWS Systems Manager
What is a custom event bus in EventBridge, and when would you create one instead of using the default event bus?
Intermediate
A custom event bus is a dedicated event bus you create separately from the default account wide event bus, often used to isolate events belonging to a specific application or business domain, which helps with organizing rules more clearly, applying more granular access permissions, and avoiding accidental cross application event matching that could occur if everything shared the same default bus.
aws events create-event-bus --name 'OrderServiceBus'
Real-world example
A company with several independent microservice teams creates a separate custom event bus for each major domain, such as orders and inventory, keeping each team's events and rules cleanly isolated from unrelated teams.
Common follow-ups: Can events be routed between different custom event buses?;How do IAM permissions differ between custom event buses?
IAM;AWS Organizations & Multi Account Strategy
How does EventBridge support cross account and cross region event routing?
Advanced
EventBridge allows you to grant permission for another AWS account's event bus to send events to your own event bus, enabling cross account architectures where a central account can receive and process events generated across many separate application accounts, and similarly, events can be forwarded to an event bus in another AWS region to support multi region event driven architectures.
aws events put-permission --event-bus-name 'CentralBus' --principal '123456789012' --action 'events:PutEvents' --statement-id 'AllowAccountA'
Real-world example
A large enterprise centralizes security related events from dozens of individual AWS accounts into a single central account's event bus, allowing its security team to monitor and respond to events across the entire organization from one place.
Common follow-ups: How do you configure a rule to forward events to a bus in a different account?;What are the security considerations when allowing cross account event access?
AWS Organizations & Multi Account Strategy;IAM
How does EventBridge Pipes differ from standard EventBridge rules for connecting sources to targets?
Advanced
EventBridge Pipes is designed specifically for point to point integrations between a single source, such as an SQS queue or a DynamoDB stream, and a single target, and unlike standard rules which are primarily for pattern based routing to multiple targets, Pipes supports built in filtering, data enrichment through a Lambda function or API call, and transformation of the event payload before it reaches the target, all configured without writing custom glue code.
aws pipes create-pipe --name 'OrderQueuePipe' --source 'arn:aws:sqs:us-east-1:123456789012:orders-queue' --target 'arn:aws:states:us-east-1:123456789012:stateMachine:processOrder'
Real-world example
A logistics company uses EventBridge Pipes to connect a DynamoDB stream directly to a Step Functions workflow, enriching each change event with additional shipping data from an API call before the workflow ever begins processing it.
Common follow-ups: What is the difference between EventBridge Pipes and a Lambda function triggered directly by SQS?;What enrichment sources are supported by EventBridge Pipes?
AWS Step Functions;Amazon Kinesis & Data Streaming