Amazon's DynamoDB serves some of the highest workloads on the planet with predictable, single-digit millisecond latency regardless of data size or concurrent operations. Like many NoSQL databases, DynamoDB did not offer support for transactions at first but added support for ACID transactions in 2018. Akshat Vig and Somu Perianayagam are two Senior Principal Engineers on the DynamoDB team and are here to talk about the team's Usenix research paper describing how they implemented support for transactions while maintaining the core performance characteristics of DynamoDB. In this show, we talk about DynamoDB transaction internals, performing user research to focus on core user needs, and staying on top of cutting-edge research as a Principal Engineer.