Title: Bulding High Performance Systems for Internet Commerce Traditional HA, high volume transactional systems have enjoyed the safe harbor of a private network. This has provided relative predictability of the workload and the ability to manage that workload as necessary. The profile of applications can be engineered and understood. Growth, peak demands, and customer behavior can be analyzed and prepared for. The workload faced by today's largest internet commerce engines is not predictable. Each minute, day, and season at Amazon.com surfaces new, interesting challenges to the design assumptions. Customers respond to external events and Amazon promotions in unexpected ways. Customers and non-customers also participate in innovating the technical environment, sometimes with the sole objective of breaking the system. Amazon.com has chosen design patterns that fit this hostile environment. The developing architecture seeks rapid innovation, unconstrained scalability, always-on availability, and low marginal cost of ownership. Amazon.com's technology platform is in an early stage, yet signficant wins have been achieved. More importantly, Amazon is learning to build long-term scalability while feature code is rolling to production every hour.