MongoDB, Express, React, Node. TypeScript end-to-end. Modern React patterns where they earn the complexity, plain React where they don’t. Node services that survive when traffic 10×s overnight. We’ve shipped MERN at every scale from beta-50 users to 5M MAU.
What kind of MERN work this is
Our MERN engagements are mostly: early-stage SaaS getting to MVP, mature SaaS products doing careful refactors, API-first products with React or React Native front-ends, internal tooling for teams that already have React fluency in-house, and real-time apps (collaboration, chat, live dashboards).
What we don’t use MERN for: marketing sites with editorial teams (use a CMS), eCommerce primary checkout (use Shopify), or anything where document-oriented MongoDB is fighting the relational shape of the data (use Postgres). We’ll tell you when MERN is wrong — including when MongoDB itself is the wrong choice and you should use Postgres with the rest of the stack.
What we build
Front-end React
React 19+ with TypeScript strict mode. Server Components where they genuinely help (data-heavy pages, SEO-relevant content), client components everywhere else — we don’t over-engineer the architecture for the sake of it. State management with Zustand or Redux Toolkit (TanStack Query for server state). Component libraries built on Radix UI primitives or shadcn/ui copy-paste base.
Node + Express
Express, Fastify, or NestJS depending on team preference and project scale. Layered architecture (controllers → services → repositories) with TypeScript end-to-end. Request validation via Zod. Error handling that surfaces useful messages instead of swallowing stack traces. Background jobs via BullMQ for queues that don’t silently fail at 3 AM.
MongoDB (or Postgres — honestly)
MongoDB via Mongoose or the native driver with TypeScript schemas. Aggregation pipelines for analytics workloads. Indexing strategy from day one. MongoDB Atlas for managed, self-hosted on AWS / GCP / Azure when compliance warrants it. We’ll happily swap Postgres in if your data is relational — the rest of the stack works fine.
Real-time when needed
Native WebSockets via Socket.IO or ws, Server-Sent Events for one-way streams. Managed Pusher or Ably when ops time is worth more than the saved subscription cost. Operational transforms or CRDTs for collaborative editing when that’s the brief (we’ve shipped Yjs-based collaboration in production).
Deployment
Vercel for Next.js front-ends, Render or Fly.io for Node services that need long-running processes, AWS or GCP for self-managed Kubernetes when scale or compliance warrants it. Docker containers with multi-stage builds. CI/CD via GitHub Actions or Vercel pipelines.
Where MERN earns the choice
- SaaS dashboards and admin platforms with complex state and lots of interactivity
- API-first products with React or React Native front-ends sharing types via tRPC or shared TypeScript packages
- Real-time products: collaboration tools, chat, live dashboards, multiplayer
- Internal tools that outgrew Retool but don’t justify a full custom backend in Go or .NET
- Content-heavy products that benefit from React Server Components for SEO
Pricing
- SaaS MVP (single happy-path, auth, billing, one to three feature areas): $40K–$90K, 8–14 weeks
- Full v1.0 SaaS (with admin tooling, onboarding, observability): $90K–$220K, 16–32 weeks
- Internal tool or API-first product: $30K–$120K, 8–18 weeks
- Mature product refactor / new feature line: $25K–$80K per scope, 4–12 weeks
Start a MERN build
Tell us about the project — what it does, scale, where it integrates. connect@prizorai.com or the form. Most of our MERN work is under NDA, so anchors and case-study reference calls happen privately after a mutual NDA.