What are different ways a Lambda function is invoked?

Difficulty: 5/10

Invocation sources, Sync vs async, Event-driven triggers

AWS Lambda functions can be invoked in multiple ways depending on the use case. Lambda supports both synchronous and asynchronous invocation models, and can be triggered by various AWS services, APIs, or directly through the AWS SDK or CLI.

Synchronous Invocation

1
API Gateway – invoke in real-time via HTTP endpoints
2
Application Load Balancer – trigger with HTTP requests
3
AWS SDK or AWS CLI – direct programmatic invocation
4
Amazon Lex – as part of chatbot workflows
5
Amazon CloudFront (via Lambda@Edge) – run code close to users

Asynchronous Invocation

1
Amazon S3 – trigger on object uploads, deletions, etc.
2
Amazon SNS – respond to published messages
3
Amazon EventBridge – handle scheduled or rule-based events
4
Amazon SES – trigger on email receipt events

Poll-Based Invocation

1
Amazon SQS – poll messages from queues and process them
2
Amazon Kinesis – consume real-time streaming data
3
Amazon DynamoDB Streams – react to data modifications

Invoke Lambda Synchronously via AWS CLI

Scenario Questions

0-2 years experience

Follow-up Questions