Permission Systems that Scale
A comprehensive guide to building scalable permission systems in TypeScript and Next.js, progressing from naive checks through RBAC and ABAC to production-grade multi-tenant authorization.
Series Overview
Published Posts
Authentication vs authorization, common permission pitfalls, the fail-closed principle, and the goals every permission system should meet.
Refactor scattered permission checks into a centralized service layer, add Next.js middleware guards, and build a defense-in-depth authorization architecture.
Build a type-safe RBAC system with TypeScript, create a unified can() function, synchronize permissions across UI and backend, and understand when RBAC reaches its limits.
Build an ABAC policy engine in TypeScript with the builder pattern, conditional permissions, and type-safe policy evaluation that replaces RBAC's limitations.
Extend ABAC with environment-based rules, field-level read and write permissions, and automatic database query filtering that eliminates duplicate permission logic.
Add multi-tenant isolation to your permission system, evaluate CASL as a library alternative, and use decision frameworks to choose the right authorization architecture.