[garethmcc]

Not entirely true. The largest use case we see for Lambda is as the compute service for an API backend provisioned with API Gateway (so a full application backend) with synchronous responses over HTTP (so rapid response provided within milliseconds) and for mundane tasks that store data in a database just like a regular web application.

The perfect use case we see repeatedly is for high volume HTTP requests to API Gateway endpoints that trigger Lambda functions that respond in less than a second depending on what compute is running.

[still_grokking]

Reads as the thing AWS wants people to use Lambda for.

Running Lambda as a back-end is one of the most expensive options (especially when high load comes in, as a parent pointed out). So no question, that's what they want to sell.