For EC2 you can run more than 1 request at the same time. For lambda it is 1 lambda per request. If you have even a few concurrent requests you lambda cost can 5-10x noting all the cold start and other times too.

Hi Stefano Check these scenario hope it works **AWS Lambda Pricing Structure** Requests: You get 1 million free requests per month. Beyond that, you're charged $0.20 per million requests. Duration: The first 400,000 GB-seconds (roughly 3.2 million seconds of compute time) are free. After that, you're charged $0.00001667 per GB-second. **if a Savings Plan is beneficial, consider these factors** * Expected Request Volume: How many times a month do you anticipate your Lambda functions being invoked? If it stays below 1 million, you won't incur request charges. * Function Execution Time: How long do your Lambda functions typically run (in milliseconds)? If they stay under 400 milliseconds (0.4 seconds), you won't incur duration charges. * Memory Allocation: How much memory (in MB) do you allocate to your Lambda functions? Optimizing memory usage can significantly impact costs. **Scenarios for Savings Plans** * Moderate Request Volume (1.5 Million/Month): If you expect to exceed 1 million requests but stay below 2 million, a Savings Plan might be worthwhile if your function execution time is high or your memory allocation is significant. * High Request Volume (5 Million/Month): Savings Plans become more attractive with higher request volumes, even if execution time is low. **Alternatives to Savings Plans** Reserved Concurrency: If you have predictable request patterns, consider Reserved Concurrency for fixed-rate pricing on Lambda capacity. However, this might not be ideal for a small application with variable usage. Official AWS Documentation: AWS Lambda Pricing: https://aws.amazon.com/lambda/pricing/ AWS Lambda Developer Guide: https://docs.aws.amazon.com/lambda/ **Additional Resources** https://lumigo.io/blog/aws-lambda-vs-ec2/