Benefits of isolated tenanted infrastructure

Bob Walker's article explores various strategies for data isolation in Software as a Service (SaaS) environments, emphasizing the importance of isolating customer data to prevent unauthorized access and minimize business risks. He discusses four data isolation methods, including using a unique customer identifier per record, tenant-specific tables, a database schema per customer, and a database per customer, and examines two application layer options: a shared application or isolated application per customer. Walker critiques the shared application and database model for its simplicity but highlights its limitations, such as application complexity, resource consumption by noisy customers, and the risk of cross-talk. He also discusses the shared application with a database per customer model, noting its appeal due to minimal code changes needed for multi-tenancy but warns of persistent challenges like connection complexity and deployment delays. Ultimately, Walker advocates for isolated tenanted infrastructure despite its higher setup time and cloud costs, as it effectively addresses risks like cross-talk and resource contention, making it a viable solution with modern tools and technologies.