Migrating auth at scale: What changes above 200K users

WorkOS has released an updated set of migration guides to assist organizations transitioning their authentication systems when scaling beyond 200,000 users, where traditional methods often fail. The refreshed guides focus on key areas such as the CLI-first import workflow, transparent proxy for large SSO fleets, webhook disable sequencing, and feature-flag-based rollout. The CLI, now the primary import tool, allows for resumable, batched imports, ensuring no data loss or duplication during migration, and adapts to various source providers like Auth0, Firebase, and Cognito. For SSO migrations, the strategy depends on the number of connections, with fewer than 15 using the Admin Portal and more than 15 adopting a transparent proxy approach to minimize IT coordination. Webhook disable sequencing is crucial to avoid overwhelming systems with queued events once migrations are completed. The use of feature flags enables a gradual rollout, allowing for testing and mitigation of any issues before fully transitioning to WorkOS. The entire process is designed to be replicable and scalable, providing a comprehensive solution for large-scale authentication migrations.