Multi-Tenant SaaS Platform

Summary

A multi-tenant SaaS architecture where multiple customers are served from a shared deployment, with PostgreSQL row-level security providing logical tenant isolation, Redis delivering per-tenant caching, and connection pooling managing the aggregate connection demand across tenant workloads. Tenant isolation, resource fairness, and operational simplicity are the three competing forces this architecture must balance.

Problem Statement

Serving multiple customers from a shared infrastructure creates a fundamental tension: tenants must be isolated from each other's data and partially from each other's resource usage, while the operator must maintain a single deployable unit and avoid per-tenant operational overhead. A noisy tenant that exhausts database connections, saturates the cache, or generates hot partition keys can degrade all other tenants. Row-level security enforces data isolation at the database layer; connection pooling bounds aggregate connection usage; cache namespacing prevents cross-tenant cache pollution.