What is AWS Lambda?

What this card says

Why do we need it?

A bakery open all night with no customers still pays rent. Always-on servers waste money the same way.

What is it?

Lambda runs your code only when an event happens. You pay for requests and duration, not idle hours.

How to do it

Write a small function, set a runtime and role, then add a trigger (S3, API Gateway, schedule…).

Lambda › Create function

Example

Photo uploaded to S3 → Lambda makes a thumbnail in seconds → idle again.