EventBridge · Event Bus

Outcome

• Event Buses & RulesDefault Event Bus + AWS Service Events
  • Explain the three sources of EventBridge events
  • Explain the standard event envelope (version, source, detail-type, detail)
  • Write a rule that matches AWS service events and routes them to CloudWatch Logs
  • Narrow a pattern to match on a specific detail field value
  • Explain why a resource policy is required on the CloudWatch Logs target
  • Explain what happens to events dropped by a failed target without a DLQ
• Event Buses & RulesCustom Event Buses + Custom Events
  • Explain why application events should go on a custom bus, not default
  • Create a custom event bus and put events onto it with PutEvents
  • Explain the required fields of a PutEvents entry (Source, DetailType, Detail)
  • Explain what happens when you omit EventBusName from a PutEvents call
  • Write rules that filter by source, detail-type, and detail field values
• Event Buses & RulesEvent Pattern Deep Dive
  • Use test-event-pattern to validate patterns before creating rules
  • Write patterns using prefix, anything-but, numeric range, and exists operators
  • Combine multiple operators in a single pattern (AND logic)
  • Explain case sensitivity in event patterns and why it causes silent failures
  • Explain why numeric patterns fail when the field value is a string
• Event Buses & RulesSchema Registry
  • Enable schema discovery on a custom event bus
  • Register a schema manually using OpenAPI 3.0 format
  • Create a new schema version and explain how versioning supports non-breaking evolution
  • Explain the value of schema-first development in event-driven systems
• Event Buses & RulesDead Letter Queues + Retry Policies + Observability
  • Explain EventBridge's at-least-once delivery guarantee and what it means for consumers
  • Configure MaximumRetryAttempts and MaximumEventAgeInSeconds on a target
  • Set up an SQS DLQ for a rule target and explain what information the DLQ message contains
  • Name the four key EventBridge CloudWatch metrics and explain what each indicates
  • Create a FailedInvocations alarm and explain why it's non-negotiable in production
• Integration LabEventBridge → Lambda
  • Explain why EventBridge → Lambda is push, not poll
  • Add lambda:InvokeFunction resource-based policy for EventBridge
  • Read the EventBridge event envelope from inside a Lambda handler (event['detail'])
  • Configure input transformer with InputPathsMap + InputTemplate
  • Identify a missing resource policy from DLQ AccessDenied output
• Integration LabEventBridge → SQS
  • Explain when EventBridge → SQS beats EventBridge → Lambda directly
  • Apply an SQS queue policy allowing EventBridge sqs:SendMessage
  • Explain the double-envelope when EventBridge → SNS → SQS and how to unwrap it
  • Configure a FIFO SQS target with MessageGroupId and explain ordering guarantees
• Integration LabEventBridge → SNS
  • Explain when EventBridge → SNS adds value over EventBridge multi-target rules
  • Configure an SNS topic policy allowing EventBridge to publish
  • Subscribe an SQS queue to SNS with the correct queue policy
  • Explain why SNS filter policies with EventBridge require a Lambda intermediary
• Integration LabEventBridge → ECS
  • Explain when event-triggered ECS task runs beat always-on ECS services
  • Create an IAM role for EventBridge to assume for ecs:RunTask
  • Explain why iam:PassRole is required for EventBridge → ECS but NOT for EventBridge → Lambda
  • Use input transformation to inject event data as container environment variable overrides
  • Describe the fan-out pattern: one event, multiple targets, zero producer changes
  • Identify a PassRole error from DLQ output and state the exact fix
• Scheduler LabFundamentals & First Schedule
  • Explain the two-role model: Scheduler Execution Role vs. Lambda Execution Role
  • Identify the correct trust principal for each role (scheduler.amazonaws.com vs. lambda.amazonaws.com)
  • Explain why swapping the trust principals causes silent failures at invocation time, not at creation time
  • Explain the difference between InvocationDroppedCount (IAM/ARN issue) and FailedInvocations (target error)
• Scheduler LabLambda as Target & Retry Logic
  • Distinguish EventBridge Scheduler from EventBridge Event Bus and CloudWatch Events
  • Write valid rate, cron, and one-time schedule expressions via CLI
  • Explain why a 6-field cron is required (vs. 5-field in standard cron)
  • Explain what happens to a one-time schedule after it fires
  • Explain why Scheduler does not backfill past-due schedules
• Scheduler LabExternal API Invocation (Lambda Wrapper)
  • Explain asynchronous invocation and why Lambda errors don't surface directly to Scheduler
  • Configure MaximumRetryAttempts and MaximumEventAgeInSeconds and explain how they interact
  • Set up an SQS DLQ and explain what the DLQ message contains
  • Explain why no DLQ means silent data loss after retry exhaustion
• Scheduler LabFlexible Time Windows & Timezone Edge Cases
  • Implement the Scheduler → Lambda → fetch(external API) bridge pattern
  • Explain why idempotency is mandatory when calling external APIs from a scheduled Lambda
  • Handle non-2xx responses by throwing (so Scheduler retries), not by returning silently
  • Explain what happens when Lambda is in a VPC with no egress path
• Scheduler LabProduction Patterns & Cost Optimization
  • Create timezone-aware schedules using IANA timezone strings
  • Explain the UTC default and how it causes silent timezone bugs
  • Configure flexible time windows and explain what they prevent
  • Explain the ? vs. * day-of-month / day-of-week constraint in cron expressions
• Scheduler Lab
  • Implement DynamoDB-based idempotency to handle at-least-once invocation
  • Bulk-create schedules programmatically via CLI loop
  • Create alarms on DLQ depth, InvocationDroppedCount, and Lambda throttles
  • Explain the three failure layers and which metric covers each
  • Calculate Scheduler invocation cost for a multi-tenant workload at scale