The API endpoint footprint is small and doesn't need to maintain any state. This makes it a prime candidate for Lamba-style webhooks. (Benefits: Auto-scaling, minimal upkeep, smaller code footprint etc.)

User will interact with a single REST endpoint (/images) through GET and PUT requests.

For Uploading the images, we need the PUT endpoint to initiate one or more upload operations. In this case, we'll trigger one or more instances of a Lambda function. (Phase 2 could utilize a Pub/Sub service with workers consuming the upload tasks - Beyond the scope of this demo)