AWS Certified Solutions Architect – Associate (SAA-C03) — Question 468

An IoT company is releasing a mattress that has sensors to collect data about a user’s sleep. The sensors will send data to an Amazon S3 bucket. The sensors collect approximately 2 MB of data every night for each mattress. The company must process and summarize the data for each mattress. The results need to be available as soon as possible. Data processing will require 1 GB of memory and will finish within 30 seconds.

Which solution will meet these requirements MOST cost-effectively?

Answer options

• A. Use AWS Glue with a Scala job
• B. Use Amazon EMR with an Apache Spark script
• C. Use AWS Lambda with a Python script
• D. Use AWS Glue with a PySpark job

Correct answer: C

Explanation

AWS Lambda is the most cost-effective choice because it charges only for the precise execution duration and allocated memory (1 GB), which easily handles the 30-second run time for 2 MB of data. In contrast, AWS Glue and Amazon EMR have higher overhead, longer cold-start times, and minimum billing periods, making them over-provisioned and far more expensive for this lightweight, event-driven task.