Read more in this article: https://dashbird.io/blog/use-aws-free/

More about AWS cost saving:

6 quick ways to save on AWS Lambda: https://dashbird.io/blog/saving-money-aws-lambda/

AWS Well-Architected Framework in Serverless: Cost Optimization Pillar: https://dashbird.io/blog/aws-well-architected-cost-optimization/

Cutting cost on AWS Step Functions: https://dashbird.io/blog/cutting-step-functions-costs-enterprise/