Neon successfully executed a complex migration of millions of user-owned projects to organization-owned accounts without any downtime or requiring customer intervention. Initially, Neon started with user accounts, but as the platform grew, the limitations of individual ownership became apparent, prompting a shift to team accounts for better collaboration and billing management. The migration required maintaining backward compatibility, especially with APIs and billing systems, ensuring that existing user-scoped API keys and billing identifiers continued to function seamlessly. To achieve this, Neon introduced the concept of "migrated organizations" and "migrated billing accounts" to transparently manage transitions without disrupting user operations. The migration was incremental and resilient, allowing for a mixed state of user and organization ownership until fully completed. The experience underscored the importance of designing a SaaS product with team accounts as the default model from the start to avoid future complexities, a lesson Neon now applies across its platform.