This five-part blog series explores the performance improvements achieved by converting sequential logic to concurrent implementation across six programming languages (Python, Node.js, Go, Rust, Java, and C) in AWS Lambda functions. The author evaluates execution times with different memory configurations, ranging from 128MB to 10240MB. The benchmark involves listing objects from an AWS S3 bucket, reading their content, and calculating execution time. Results show that Rust and C perform best overall, with Python and Node.js also showing strong performance. The author provides a subjective review of developer experience and combines it with objective performance results to create a final ranking. The series demonstrates significant improvements in execution time when moving from sequential to concurrent implementations.