Full-Stack Developer · Wyckoff, NJ

Build. Engineer. Ship.

5+ years shipping full-stack production products — web apps, SaaS platforms, AI-powered tools, and browser extensions. I own the entire stack: architecture, AI integration, Stripe billing, cloud deployment and everything in between. 6+ live products. Real users. Real revenue.

6+
Live Products
5+
Years Coding
4
AI Products
View Work ↓ ● Open to new roles
JavaScriptTypeScriptNode.jsReactNext.jsOpenAI APIStripeFirebaseSupabasePostgreSQLVercelAWS · AzureChrome ExtensionsClerk AuthC++ · PythonTailwind CSSFramer Motion JavaScriptTypeScriptNode.jsReactNext.jsOpenAI APIStripeFirebaseSupabasePostgreSQLVercelAWS · AzureChrome ExtensionsClerk AuthC++ · PythonTailwind CSSFramer Motion

What I Build

Core Capabilities
⚡
Web Apps & SaaS Platforms
Full-stack web applications built for scale — from landing pages and marketing sites to full SaaS products with dashboards, user management, and billing.
Next.jsReactNode.jsPostgreSQLTailwind
🤖
AI Integration & LLM Products
Production AI features using OpenAI and other LLM APIs — chatbots, document analysis, content generation, fact-checking, and automated workflows deployed to real users.
OpenAI APIPrompt EngineeringRAGStreaming
💳
Payments & Subscription Billing
End-to-end monetization with Stripe — subscription plans, one-time purchases, webhooks, trial periods, and customer portals. Built for products that earn revenue.
StripeWebhooksSubscriptionsBilling Portals
☁️
Cloud & DevOps
Deploying and managing production infrastructure on Vercel, AWS, and Azure — CI/CD pipelines, environment configs, edge deployments, and serverless functions.
AWSAzureVercelCI/CDServerless
🔐
Auth & User Management
Secure authentication and user flows using Clerk, Firebase Auth, and Supabase — including OAuth, role-based access, session handling, and email verification.
ClerkFirebase AuthSupabaseOAuthRBAC
🧩
Browser Extensions
Published Chrome extensions with real-world monetization — from Manifest V3 architecture to Chrome Web Store publishing, premium paywalls, and live user bases.
Chrome APIManifest V3WebpackFirebase
🗄️
Database & Backend Architecture
Designing and managing databases for production — PostgreSQL, Supabase, Neon, and Firebase. Schema design, API architecture, and data modeling for real-world apps.
PostgreSQLSupabaseNeonFirebaseREST APIs
🎨
UI/UX & Frontend Design
Pixel-perfect interfaces with smooth animations and professional design — from component systems to full marketing sites, with attention to detail and user experience.
Tailwind CSSFramer MotionFigmaResponsive

Selected Work

07 Projects · By Complexity
01
AI SaaS · Web App
ExamTutorAI
Next.jsOpenAISupabaseStripeClerk
02
Security Platform · AI
VulnerabilityView
Next.jsClerkPostgreSQLOpenAI
03
AI Extension · Real-Time
ConfidenceCheck
Chrome APINext.jsOpenAISupabase
04
AI Tooling · LLM Evaluation · GitHub
AI Eval Dashboard
Next.jsOpenAITypeScriptPostgreSQL
05
Chrome Extension · Monetized
Walculator
JavaScriptFirebaseStripeChrome API
06
B2B Platform · Wholesale
Black Inn Distribution
JavaScriptNeonResendVercel
07
Agency · Web Design
Karahan Design
Next.jsTailwindFramer MotionTypeScript

Publications

01 Document
Software Engineering · Design Documentation
Library Information & Administration System (LIAS)
Semih Aksehirli, Nihat Karahan, Mohammed Mostofa
William Paterson University · CS 3500 Software Engineering · Spring 2026
A full object-oriented design and documentation deliverable spanning the complete software development lifecycle — requirements, six use cases, communication diagrams, nine UML class diagrams, and C++ implementation skeletons.
C++UMLOODSystem Design
Read documentation ↗

What makes
me different.

I don't just write code — I ship complete products. From the first database migration to the Stripe webhook to the production deploy, I own the whole thing. No handoffs. No gaps.

→
Full ownership, end to end
I architect, build, deploy, and maintain entire products solo. Schema design, API, frontend, auth, payments, cloud — all of it.
→
AI that ships to real users
Not demos or experiments — I've built and deployed multiple AI-powered products with real user bases using OpenAI, streaming responses, and prompt engineering.
→
Commercial product mindset
I've built paywalls, subscription flows, billing portals, and monetized Chrome extensions. I understand what it takes to make software people pay for.
→
Fast, independent, and reliable
I move quickly without cutting corners. I've shipped across fintech, security, edtech, B2B, and agency work — I adapt fast to new domains.

Expertise

05 Areas
01
Full-Stack Engineering
End-to-end product ownership from database schema to pixel-perfect UI
02
AI & LLM Integration
Production-grade AI products — OpenAI, prompt engineering, real users
03
Payments & Auth
Stripe subscriptions, Clerk, Firebase Auth — complete billing flows
04
Cloud & DevOps
Vercel, AWS, Azure — CI/CD, edge deployments, serverless
05
Browser Extensions
Published Chrome extensions with monetization, auth & live user bases
Currently open to new roles
Full-Stack Engineering AI / ML Engineering Product Engineering Software Engineering Frontend Engineering

Let's
build
something.

I'm actively looking for software engineering, AI, and product engineering roles. If you're building something great, I'd love to talk.

Connect on
LinkedIn
↗
Agency
Karahan Design
↗
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