Emrah Sönmez

Full-Stack Developer · React, Vue, Next.js, .NET Core, Node.js · AI-assisted development (Claude Code)

Verified with LinkedIn

I have been developing software for 12 years. I build web applications with React, Vue, Next.js and Nuxt.js, backend services with .NET Core and Node.js, and data layers with PostgreSQL and MSSQL. I have been freelancing since September 2024 and take on work end to end: requirements analysis, architecture, development, going live and maintenance. Some of my recent work: • Two production applications for a housing cooperative with 639 members: an apartment allocation (lottery) platform and a member/financial data audit system. Vue 3, TypeScript, Supabase/PostgreSQL, 18 serverless edge functions, Row Level Security and automated deployment with GitHub Actions. About 15,000 bank transactions are matched through a human-approved LLM data pipeline. • A 3-panel management system for a payment institution (Payment Facilitator): back-office, member merchant and representative panels. About 90 screens, 130+ permission definitions, real-time transaction tracking with SignalR, a type-safe service layer generated from OpenAPI. • A B2B platform where corporate customers run bulk SMS campaigns: .NET Core microservices, Turkcell, Vodafone and Türk Telekom operator integrations, about 4 billion SMS per year. • An appointment, payment and e-commerce platform for dental clinics: Next.js, SSR, multilingual structure. Running live. On the corporate side, at Fibabanka I built the infrastructure that 20+ teams used to migrate a 2,000+ page Core Banking application to React. At Doğuş Teknoloji I was the technical lead of a 5-person frontend team. At Ultia, part of the Turkcell Group, I led the modernization of a 5-year-old no-code platform. What I can do: • Web application, SaaS and admin panel development (React, Vue, Next.js, Nuxt.js) • Backend and API development (.NET Core, Node.js, REST, GraphQL) • Payment, ERP, CRM and third-party service integrations • Database design (PostgreSQL, MSSQL, Supabase) • Mobile applications (React Native) • Modernization of legacy projects, performance improvement and bug fixing • Corporate websites and e-commerce How I work: I do AI-assisted development with Claude Code. Every piece of code the agent writes goes through type checking, linting and code review, and I keep the project's rules and documentation in writing. This way I move fast without compromising quality. I deliver the code, documentation and deployment infrastructure in full, so that another developer can easily take over when the project is done. Details and projects: emrahsonmez.com

Experience

Freelance Full-Stack Developer Serbest Çalışma Sep 2024 – Present
Housing cooperative digital transformation program (February 2026 – present): an apartment allocation (lottery) platform and member/financial data audit system for a cooperative with 639 members. Vue 3, TypeScript, Supabase/PostgreSQL, 39 SQL migrations, 37 RLS policies, 18 serverless edge functions, automated deployment with GitHub Actions. About 15,000 bank transactions are matched with a human-approved LLM data pipeline; financial integrity with integer arithmetic and an invariant chain. Payment platform (September 2024 – February 2026): back-office, member merchant and representative panels of a Payment Facilitator payment infrastructure. About 90 screens, RBAC with 130+ permissions, real-time transaction tracking with SignalR, a type-safe service layer with OpenAPI codegen, a shared data grid across 30+ screens and Excel/CSV export.
Expert Frontend Developer Ultia A.Ş. (Turkcell Grubu) Mar 2024 – Aug 2024
Frontend leadership of a no-code platform that had been developed for 5 years within Turkcell. In a 4-person team, planned and carried out the technology stack modernization and refactor program. Optimized render time that exceeded 1 minute when adding components, built the hot reload infrastructure, split overgrown files into a modular structure; architectural updates in the drag-and-drop canvas, form builder, action flow and theme editor modules. React, TypeScript, Redux. The project was terminated by company decision.
Senior Frontend Developer Doping Hafıza Oct 2023 – Mar 2024
Development of the main application and the React Native mobile app of an online education platform serving 160,000+ students on web, mobile and tablet. Rewrote from scratch, with current technologies, the management applications that feed the main platform, moving them off the legacy structure (sole frontend owner): a content management panel with granular RBAC, a parent tracking app, a call center operations panel, and a corporate site with Next.js + Strapi CMS. Data layer with OpenAPI codegen and React-Query.
Principal Software Developer Doğuş Teknoloji May 2022 – Oct 2023
Two digital products within Doğuş Holding; technical leadership of a 5-person frontend team in a project team of about 15. Sensat.com (vehicle buying-selling and rental marketplace, about 100K visits per day): Nuxt.js SSR architecture, a back-office built from scratch with Vue 3, granular RBAC, SignalR notification system. Zubizu (campaign platform with millions of users): corporate site with Next.js + Strapi CMS, React + Redux back-office, Storybook component documentation, Keycloak SSO.
Senior Frontend Developer Fibabanka Aug 2021 – May 2022
Migration of the Core Banking application used by the bank's employees from a proprietary interface language to a React-based web architecture. Frontend infrastructure of the 2,000+ page transformation program with 20+ teams taking part: React project skeletons, a shared architectural standard, component and helper libraries, Storybook documentation. Page development time dropped from 1 week to under 1 day, hot reload from 2 minutes to instant; about 30% improvement in render time.
Full-Stack Developer ITS Bilişim Jun 2016 – Jul 2021
Web, mobile and desktop applications in ticket sales, insurance, energy monitoring and retail electricity. First-time introduction of React and React Native in a .NET-heavy organization; after the pilots they became the standard stack for all new projects. enucuzu.com flight and bus ticket marketplace (ASP.NET MVC, C#, then React and React Native), solar and wind power plant energy monitoring dashboards (Node.js, GraphQL, TypeORM, MSSQL, Redis), retail electricity platform with EPİAŞ integration (WPF, DevExpress, C#). CI/CD, JWT/OAuth2, RESTful API design.
CRM Developer / Technical Consultant AGC Yazılım Sep 2014 – Jun 2016
Custom solutions, workflow automation and setup/integration consulting on Microsoft Dynamics CRM and Resco platforms for corporate clients. Clients included İzmir Türk Koleji, IKSV, Medical Park, ASAY and Ünlü Teknik.

Education

Ege Üniversitesi Bilgisayar Mühendisliği (Lisans) 2008 – 2013

Portfolio

emrahsonmez.com — Personal site and project showcase emrahsonmez.com
My personal website where I describe my experience, projects and the way I work.
Housing Cooperative Lottery and Financial Audit Platform emrahsonmez.com
Two production applications for a cooperative with 639 members: a multi-round apartment allocation (lottery) platform and a member/financial data audit system. Vue 3, TypeScript, Supabase/PostgreSQL, Row Level Security, 18 edge functions, live status with Pusher, matching of about 15,000 bank transactions with a human-approved LLM. Developed with AI assistance using Claude Code. A closed, client-specific system; a detailed description is on my personal site.
Payment Institution Management Panels (PF) emrahsonmez.com
Back-office, member merchant and representative panels for a Payment Facilitator infrastructure. About 90 screens, RBAC with 130+ permissions, virtual POS and reconciliation modules, real-time transaction flow with SignalR, 3-channel 2FA, OpenAPI codegen. A closed, client-specific system; a detailed description is on my personal site.
B2B Bulk SMS Platform emrahsonmez.com
A platform where corporate customers run credit-based bulk SMS campaigns. .NET Core microservices, resilience with Polly, Turkcell, Vodafone and Türk Telekom integrations, public REST API, multi-tenant structure. 100+ companies, about 4 billion SMS per year. A closed, client-specific system; a detailed description is on my personal site.

AI agents

Claude Code Software / code Claude Code CLAUDE.md proje kuralları GitHub Ajan: iyi tanımlanmış görevleri uygular (bileşen, API uç noktası, SQL migration, refactor, dokümantasyon), kod tabanında arama ve analiz yapar. Ben: mimariyi ve görev planını belirlerim, projenin yazılı kurallarını (CLAUDE.md, modül README) tutarım, ajanın her çıktısını tip denetimi, lint, tarayıcı testi ve kod incelemesinden geçiririm. Canlıya giden her satırın sorumluluğu bende.

Agent and model details are the expert's own statement.