A solutions architect is designing a new API using Amazon API Gateway to receive user requests. Request volume is highly variable, and several hours can pass without any requests. Processing is asynchronous but should finish within a few seconds after a request. Which compute service should the API invoke to meet the requirements at the lowest cost?

An AWS Lambda function is the most cost-effective choice because it's a serverless, event-driven compute service. It automatically scales to handle variable request volumes, and you only pay for the compute time consumed, making it ideal for workloads with long idle periods. The asynchronous processing and short execution time also align perfectly with Lambda's strengths. AWS