EventBridge & orchestration

Route events to automated responses; Step Functions.

Event-driven automation is the connective tissue of AWS operations. Amazon EventBridge routes events between services by rules, and mastering it is how a DevOps engineer wires detection to response across the whole estate.

The event bus

EventBridge is a serverless event bus: AWS services, your applications, and SaaS partners emit events, and you write rules that match events and route them to targets — Lambda functions, SSM Automation runbooks, SNS topics, Step Functions, and more. It also supports scheduled rules (cron) for recurring tasks. The power is decoupling: a producer emits an event without knowing who consumes it, and adding a new reaction is a rule change, not a code change to the producer. This is the mechanism behind automated remediation, notifications, cross-service workflows, and self-healing — one event can trigger many independent, parallel reactions.

# On a high-severity GuardDuty finding, isolate the resource + page on-call.
aws events put-rule --name gd-critical \
  --event-pattern '{"source":["aws.guardduty"],"detail":{"severity":[{"numeric":[">=",7]}]}}'
 
aws events put-targets --rule gd-critical --targets \
  'Id=isolate,Arn=arn:aws:states:...:stateMachine:ir-runbook' \
  'Id=page,Arn=arn:aws:sns:...:oncall'
# One event → parallel reactions (remediate + notify), decoupled and rule-driven.

Orchestration and the operations loop

For multi-step workflows, Step Functions orchestrates a sequence of actions (with retries, branching, and error handling) that an EventBridge rule can trigger — ideal for complex remediation or deployment orchestration. Putting the whole section together: CloudWatch and X-Ray provide observability, alarms and Config findings and GuardDuty produce events, EventBridge routes them, and Lambda/SSM/Step Functions execute the response — a continuous, automated operations loop. This event-driven architecture is what enables self-healing systems, fast incident response, and hands-off operations at scale, and it recurs throughout the professional-level material because it is how modern AWS operations actually work: detect, route, respond, all automatically and auditably.