The Amazon Cryptographic Libraries (ACL) team builds the cryptography that AWS services and a growing open-source community depend on, including AWS-LC, our FIPS-validated open-source libcrypto. As a Software Development Engineer you will shape the cryptographic implementations that run across all of Amazon and a growing number of open-source consumers. You will also help pioneer how we apply generative AI to open-source library security. Few teams let an SDE ship code this foundational: it runs on effectively every AWS service, ships to open-source partners, and has to be both correct and fast. Key job responsibilities - Design, implement, test, and maintain cryptographic functionality in AWS-LC and related libraries used across Amazon and by external open-source consumers. - Own features end to end, from design through code review, testing, release, and operational support, on a codebase where correctness is non-negotiable. - Build and apply generative-AI tooling to open-source library security, including automated CVE backports, vulnerability triage, and code review at scale. - Raise the bar on code quality, test coverage, and engineering practices for a security-critical, widely deployed codebase. - Collaborate with Applied Scientists, security engineers, and partner teams (AWS services and open-source consumers) to land changes safely at scale. A day in the life You pick up a feature or fix that will ship into a library running on effectively every AWS service. You work through the design with teammates, write and test the implementation, and put it through rigorous code review. Alongside feature work, you improve the automation that keeps our many release branches secure, including AI-assisted tooling for backporting fixes and triaging vulnerabilities. Your changes are validated for FIPS and backed by formal verification, so you operate at a correctness bar most engineers never encounter. About the team ACL owns AWS-LC (Amazon's FIPS-validated libcrypto), the Amazon Corretto Crypto Provider (ACCP), and managed third-party cryptographic libraries. Our software is the cryptographic foundation under nearly every AWS service and a growing set of external open-source projects. We partner closely with Amazon's Automated Reasoning Group on formal verification and with Applied Scientists who own algorithm-level and assembly performance work, so engineers on the team get both enormous reach and deep technical depth.