These questions are independently created for study purposes. They are not official AWS exam questions, actual exam questions, leaked questions, or exam dumps.
CLF-019
Which of the following is the most appropriate characteristic of AWS Lambda?
Choices
Explanation and answer
Read the explanation and correct answer (spoiler — try answering first)
Correct answer: A. You can run code without managing servers.
Explanation
AWS Lambda is a serverless compute service that lets you run code in response to events without managing servers.
Per-choice explanations
A. You can run code without managing servers.
Correct. Lambda lets you run code without servers.
B. It manages only DNS records.
Incorrect. DNS management is handled by Amazon Route 53.
C. You purchase and install physical servers.
Incorrect. There is no need to purchase physical servers.
D. It mails invoices to users.
Incorrect. It is not a service for mailing invoices.
Practical Use
AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. You deploy code as functions, which are triggered automatically by events such as a request to Amazon API Gateway, a file upload to Amazon S3, a message arriving on Amazon SQS, or a scheduled event from Amazon EventBridge. Billing is based on the execution time actually used in milliseconds (about 0.0000002 USD per request), so for small workloads with few requests or event-driven processing, the cost can be significantly lower than Amazon EC2. A key characteristic is that the maximum execution time is limited to 15 minutes. Long-running processing (such as batch jobs or video transcoding) is not a good fit, and in that case Amazon EC2 or Amazon ECS with AWS Fargate becomes the choice. Supported runtimes officially include Node.js, Python, Java, Go, Ruby, and .NET. You can also run any language using a custom runtime. The default concurrent execution limit is set per AWS Region, and cold-start latency can occur when traffic increases rapidly. On CLF-C02, this content is asked as a question that requests which option lets you run code without managing servers, or which is a correct characteristic of Lambda. Understanding the concept of serverless itself (no infrastructure management, event-driven, per-millisecond billing, and an execution time limit) is important. Common distractors include Amazon EC2 (where you need to manage servers) and Amazon ECS (where you need to manage containers).