Launched in June of 2015, s2n is an AWS open-source implementation of the TLS and SSL network security protocols, which focus on security, simplicity, and performance. With development led by engineers from Amazon EC2, Amazon S3, Amazon CloudFront, and AWS security and cryptography services, s2n is a unique opportunity to observe how we develop and test security and availability for critical software at AWS. Learn how we iterate and code, how we automate software verification beyond the usual code reviews, and how open source works at Amazon.