The article explores the design and management of a shared application environment in a database-per-user architecture, a classic SaaS model where a single application environment is shared among all users. This approach offers simplicity and operational efficiency, as there's just one system to manage initially, which can be attractive for smaller engineering teams. However, it brings challenges like maintaining consistent schema versions across user databases and navigating data residency issues without geographic constraints. The shared-environment strategy emphasizes the importance of a central catalog database for managing user data and routing queries, simplifying the security model by centralizing access decisions. It also highlights the potential for operational complications, such as schema upgrades, which require careful planning and testing to avoid disruptions. The article suggests that while the shared environment simplifies some aspects, it introduces complexities that must be managed, making it suitable for certain scenarios but not all. This piece is part of a broader series on database-per-user architectures, with future articles set to discuss isolated application environments.