In the SaaS industry, ensuring tenant isolation is crucial for maintaining data security and operational efficiency in multi-tenant environments. Kong addresses this challenge by employing various database strategies, such as separate databases, shared databases with separate schemas, and shared databases with shared schemas, each with its own trade-offs regarding resource requirements and data isolation. The implementation of row-level security (RLS) in PostgreSQL is highlighted as a refined approach to maintain tenant data isolation by applying security checks at the row level, ensuring that queries are processed only for authorized data. Kong uses a microservice architecture and leverages tools like Golang and TypeScript to facilitate the adoption of RLS, ensuring seamless integration and secure data handling. The article emphasizes the importance of strong testing frameworks to ensure smooth transitions to RLS and the necessity of internal tools to automate tenant scoping in database queries, ultimately advocating for RLS as a robust solution for tenant data security.