Create thumbnails with Lambda.
A good use case is media streaming and to make things faster. Therfore serverless functionality like Lambda provides support by serverless code, we call it Function as a Service (FaaS).
E.g. to encode video data, transcode video or picture formats to multiple formats, like in this example above or to catalog video metadata or stream video to clients.
The code will be triggered by an event. If the event status occurs, the code e.g. written in Python starts to run and you pay for the used compute time. An event could be a file upload in a S3 bucket (Source Bucket). Following this trigger the Lambda function act in relation to an Execution Role, „Who can do what with the Lambda function„. It picks up the uploaded file and starts transcoding and outputs the files to a target S3 bucket.