Unified Grid: How We Re-Architected Slack for Our Largest Customers

This post details the technical challenges and architectural changes required to transition Slack's backend and clients from a workspace-centric to an org-wide data model for Enterprise Grid users. It describes the 'Unified Grid' project, including the creation of a new boot API for org-wide data, updates to the API framework to support the new model, and strategies for fixing APIs: allowing workspace-agnostic APIs to function, prompting users to select a workspace for workspace-specific APIs, and iterating over relevant workspaces as a fallback. It also discusses the decision to cap relevant workspaces at 50 for performance reasons and the two-pass approach for API migration (internal usage then full correctness).