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.
API Gateway – invoke in real-time via HTTP endpoints
Application Load Balancer – trigger with HTTP requests
AWS SDK or AWS CLI – direct programmatic invocation
Amazon Lex – as part of chatbot workflows
Amazon CloudFront (via Lambda@Edge) – run code close to users
Amazon S3 – trigger on object uploads, deletions, etc.
Amazon SNS – respond to published messages
Amazon EventBridge – handle scheduled or rule-based events
Amazon SES – trigger on email receipt events
Amazon SQS – poll messages from queues and process them
Amazon Kinesis – consume real-time streaming data
Amazon DynamoDB Streams – react to data modifications