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I will build a complete authentication system with otp firebase clerk or jwt
Anuj Singh
About this gig
I build secure, production-ready authentication systems for web applications from simple email/password login to OTP-based auth, Firebase, Clerk, and full role-based access control.
Authentication is the foundation of every application. A poorly built auth system is a security risk. I build it right the first time.
WHAT I BUILD
Email and password authentication with JWT
OTP-based login via SMS or email
Firebase Authentication (Google, GitHub, email)
Clerk integration with pre-built UI components
Role-based access control (admin, user, moderator, custom roles)
Protected routes and middleware
Refresh token rotation for persistent sessions
Password reset and email verification flows
OAuth / social login (Google, GitHub, Facebook)
Multi-factor authentication (MFA)
TECH STACK
Frontend: Next.js, React, TypeScript
Backend: Node.js, Express, NestJS
Auth libraries: Clerk, Firebase Auth, Passport.js, NextAuth
Token handling: JWT, refresh tokens, cookie-based sessions
Databases: MongoDB, PostgreSQL, Firebase Firestore
OTP: Twilio, nodemailer, custom OTP logic
SECURITY STANDARDS I FOLLOW
Passwords hashed with bcrypt (never stored plain)
JWT stored in httpOnly cookies (not localStorage)
Get to know Anuj Singh
Anuj Singh
Modern fullstack website and web app development
- FromIndia
- Member sinceJul 2025
- Avg. response time1 hour
Languages
Hindi, English
Hi, I’m Anuj, a full-stack web developer specializing in building modern, responsive, and user-friendly websites and web applications. I work with React.js, Next.js, TypeScript, Tailwind CSS, Node.js, MongoDB, and Firebase to deliver reliable and scalable solutions.
I handle both frontend and backend development, focusing on clean UI, smooth user experience, and well-structured code.
Some of my strengths are problem-solving, clean UI/UX design, real-time functionality using WebSockets, and API integration. I take pride in writing scalable, efficient code and bringing creative ideas to life.
My Portfolio
Other Software Development Services I Offer
FAQ
Which auth method should I use — Clerk, Firebase, or custom JWT?
Clerk is best for Next.js projects where you want a fully managed solution with a beautiful UI and minimal setup. Firebase Auth is great for projects already using Firebase. Custom JWT gives you full control and works with any backend — best for complex role systems or when you want zero vendor depe
Can you add authentication to my existing application?
Yes — this is one of the most common requests I get. Share your current tech stack and I will integrate the auth system cleanly without breaking your existing code. I write modular auth middleware that plugs into your routes without restructuring your whole project.
Is the authentication secure enough for a production app?
Yes. Every system I build follows current security best practices — bcrypt password hashing, httpOnly cookie JWT storage, rate limiting on sensitive endpoints, input validation, and CORS configuration. I have built auth for production SaaS products, not just demo projects.
How is the code delivered?
You receive a GitHub repository with a clean folder structure, env variable setup instructions, and full documentation of every auth flow. You own the code completely.
