Tenancy, billing, and isolation decisions you can't easily undo. A field guide from production SaaS builds.
Multi-tenancy is the architectural decision that shapes everything else in a SaaS product — data isolation, billing, scaling, and security all hang off it.
At NOYT India we build these systems in production — with evaluation, cost control, and observability baked in from day one. Below we share the patterns that have held up under real traffic, the trade-offs we weigh, and the mistakes worth avoiding.
If you're planning something similar, the short version is: start from the bottleneck, instrument everything, and ship in small, reversible steps.