Ceyhun Türkmen

Profile

Production-focused Full Stack Developer specialized in e-commerce, enterprise SaaS, and marketplace platforms. Deep expertise in Next.js SSR/SSG, Node.js, and PostgreSQL; strong command of JWT/RBAC authentication, query optimization, transaction management, and modular backend architecture. Independently manages the full software development lifecycle from requirements analysis to CI/CD deployment. Integrated artificial intelligence into a personal portfolio site, building an AI assistant that responds to visitors in real time; achieved Lighthouse 90–100, SEO and Accessibility 100/100 scores across all projects.

Technical Skills

Frontend:React, Next.js (SSR/SSG), TypeScript, JavaScript (ES6+), Redux Toolkit, Tailwind CSS

Backend:Node.js, Express.js, RESTful API, JWT, RBAC, TOTP / 2FA, MVC Architecture, Indexing & Query Optimization, Transaction Management, Logging

Database:PostgreSQL, MongoDB, MySQL · ORM: Prisma, Sequelize, Mongoose

DevOps:Docker, CI/CD, VPS, Linux, Nginx, PM2, Git / GitHub

Performance & SEO:Core Web Vitals, WebP/AVIF, Lazy Loading, Code Splitting, Technical SEO

AI Integration:Anthropic Claude API, Prompt Engineering, Conversational AI, Streaming Responses

Testing:Jest, Supertest

Experience

Freelance Full Stack DeveloperRemote | 2024 – Present

Designed, developed, and deployed 8+ production-ready commercial platforms across e-commerce, corporate training, and marketplace categories.
Improved backend response times through PostgreSQL index strategies and query optimization; established structured logging infrastructure to systematize error tracking.
Earned placement on Bionluk platform's Rising Stars and Most Loved Freelancers lists, recognized for outstanding client satisfaction.

Core Stack:Next.jsReactNode.jsPostgreSQLPrismaDockerNginxVPS

TAV Security – Training & Exam PlatformEnterprise | 2025

TAV Private Security Services · Airport Security Personnel Training

Built a JWT-based RBAC system for Administrator / Trainer / Personnel roles; implemented TOTP-based 2FA with Google Authenticator integration to meet enterprise security requirements.
Developed interactive exam modules featuring an object-annotated baggage inspection simulation, along with a result tracking and performance measurement engine to automate training assessment.

Stack:ReactRedux ToolkitNode.jsExpress.jsMySQLJWTRESTful API

E-Commerce Platforms6+ Active Commercial Projects

İşPool · BalkoLüx · Moda Perde · NowArt Plicell · RosallieBaby · BarScarf

End-to-end development of product & order management, admin panel, and secure payment infrastructure with Iyzico payment integration.
Elevated Core Web Vitals and SEO scores above competing sites using Next.js SSR and image optimization techniques (WebP/AVIF, lazy loading, code splitting); achieved mobile LCP below the target threshold.

Stack:Next.jsReactNode.jsPostgreSQLPrismaDocker

Bulursa – Freelance Marketplace PlatformTeam Project | 2024 – Ongoing

Participated in sprint-based development using Agile (Scrum) methodology; progressed through task planning and an iterative delivery model.

Featured Projects

Jhun.com.tr – AI Assistant-Powered Portfolio Next.js · SSG · Anthropic Claude API · Multilingual (TR/EN)

Personal corporate portfolio and blog platform. Features an AI assistant powered by the Anthropic Claude API that answers visitor questions about the CV, projects, and experience in real time; fully SSG-optimized with a Lighthouse 100/100 SEO score.

AdsToWinNext.js · Node.js · PostgreSQL

Role-based rewarded advertising platform with balance tracking and campaign management. Multiple user roles and real-time balance updates.

VANET Cyber Attack SimulatorOMNeT++ · SUMO · C++

Graduation project — Academic simulation modeling cyber attacks such as DoS, message tampering, and identity spoofing in vehicular ad hoc networks (VANET).

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