Migrating the Atlassian Identity Platform to AWS

This post details the strategic approach and learnings from migrating Atlassian's Identity Platform, specifically the User Management monolith, from on-premises data centers to AWS. It outlines the 'master plan' architecture, guiding principles for platform development (e.g., multi-product benefit, limited API exposure, adherence to industry standards, scale and resilience), and the use of EventStorming for shared understanding. It also describes decomposition strategies, including vertical and horizontal slicing, and the phased migration of business logic and domain models to AWS.