Codify SaaS Blog - Page 2
Code-first guides and deep dives on building B2B SaaS products, designing APIs, scaling web apps, and modernizing legacy software.
How to Build Role-Based Permissions for SaaS Beyond Simple Admin and User Roles
The admin/user role split works until your first enterprise customer asks for workspace-level roles, resource-level permissions, and a role hierarchy that does not require a database migration. Here is the RBAC system we built instead.
Next.js App Router vs Pages Router — We Rebuilt the Same SaaS Feature in Both
We rebuilt a data-heavy SaaS dashboard in both Next.js App Router and Pages Router with the same feature set. Here are the performance numbers, auth patterns, and the migration traps that caught us along the way.
SaaS Dashboard Architecture in Next.js — How We Structure Complex Admin Interfaces
Most SaaS dashboards start simple and become unmaintainable. Here is the layout hierarchy, data fetching strategy, state management, and component architecture we use to keep them clean.
Next.js Internationalization for SaaS — How We Support Multiple Languages and Currencies
Adding i18n to a Next.js SaaS is more than translating strings — you need locale routing, RTL layout support, currency formatting with proper separators, pluralization rules, and a translation workflow that scales. Here is the full implementation with next-intl.
How to Build a SaaS Billing Portal — Stripe Customer Portal vs Custom Implementation
Stripe Customer Portal works out of the box and covers most billing needs. But it has branding limits and rigid flows. Here is how to decide between hosted portal and custom UI — with implementation code for both.
File Upload Architecture for SaaS — Direct S3 Upload With Presigned URLs in NestJS
Most SaaS apps funnel file uploads through their application server — paying the bandwidth cost twice and blocking request threads while files transfer. Here is the presigned URL approach with NestJS, frontend upload, validation, virus scanning, and image processing.
How to Build a SaaS Onboarding Flow That Actually Converts New Users
Most SaaS onboarding flows are technically broken — they lose state on refresh, have no resume logic, and track nothing. Here is the full implementation with URL-based steps, localStorage persistence, conditional branching, and analytics.
Building a Real-Time Notification System — WebSockets vs SSE vs Polling in NestJS
Most SaaS teams reach for WebSockets the moment they need any real-time behaviour. Often they need SSE. Sometimes they just need polling. Here are all three implementations in NestJS with the exact decision framework for when each makes sense.
Event-Driven Architecture in NestJS — When to Use It and Full Implementation
Event-driven architecture sounds fancy, but most developers overcomplicate it. Here is what event-driven means (and does not mean) in a NestJS SaaS, with full code you can use today.
NestJS Project Structure: The Exact Folder Setup We Ship
The default NestJS project structure is fine until about 20 controllers, then it quietly turns into a swamp. Here's the exact 3-layer folder structure we use in production — Core, Shared, and Feature modules — with the rules that keep it clean as the team grows.
PostgreSQL Performance for SaaS — 8 Query Optimizations From a Real Slow Dashboard
The dashboard took 8 seconds to load and the client was, reasonably, unhappy. We did not shard the database or add caching or rewrite anything. We fixed the wrong index, killed an N+1, and replaced a correlated subquery. Eight seconds became 340ms. Here is exactly how.
PostgreSQL Row-Level Security for SaaS — Complete Implementation Guide
PostgreSQL Row-Level Security moves tenant isolation out of application code and into the database, where a forgotten WHERE clause can't undo it. Here's the complete production implementation — policies, NestJS integration, performance, testing, and rollout.