Selman Altinay

Available to hire

Senior .NET full-stack developer: ERP & e-commerce integrations, AI automation, web apps & APIs.

About

Senior .NET full-stack developer: ERP & e-commerce integrations, AI automation, web apps & APIs.

I’m Selman Altinay, a Belgium-based software engineer (Rui Codex, Tielt-Winge) building business software end to end: web applications and APIs in C#/ASP.NET Core with SQL Server or PostgreSQL, and integrations between systems that don’t talk to each other.

Delivered work includes a modular web ERP (purchasing, sales, export, finance, warehouse), real-time sync between marketplaces (Trendyol, Hepsiburada, N11) and Netsis accounting with automated e-invoices and e-waybills, a PrestaShop pipeline to accounting and four carriers, PLC/SCADA data collection for a machining facility, and EveryTranslate, Rui Codex’s own AI translation SaaS. Rui Codex also publishes its own apps and games on Google Play.

I also build AI/n8n workflow automation.

How I work: async-first, written communication (English, Turkish, basic Dutch), short milestones. Work done inside a client’s own system (their ERP, webshop or app) stays there as source code they can use and modify; Rui Codex’s own products and reusable components are licensed for use (a source-code buy-out can be quoted on request). 12+ years of experience.

Case studies: Website not available. Sign in: https://www.twine.net/signup

  • Joined October 2026

Languages

  • EnglishAdvanced
  • TurkishFluent
  • DutchBeginner

Industry experience

  • Software & Internet
  • Manufacturing
  • Retail
  • Wholesale & Distribution
  • Gaming

More experts in Leuven, Belgium

Projects · 7

PrestaShop ↔ accounting ↔ carriers integration

A PrestaShop store was processing orders, invoices and shipments by hand. I built an integration service that syncs orders, invoices and inventory bidirectionally between PrestaShop and Netsis Accounting, and connects four cargo providers (Aras, PTT, Sendeo, MNG) with unified shipment tracking. Built with Python-based APIs, it automated the whole order-to-shipment pipeline. Role: Lead developer (Rui Codex) Skills: Python, REST API, PrestaShop, E-commerce integration, Accounting integration, Carrier APIs Link: https://www.twine.net/signin

  • Back-End Developer
  • Full Stack Developer
  • Software Engineer
  • +1
Marketplace to accounting integration (real-time sync, e-invoices)

A multi-marketplace e-commerce operation was entering inventory, orders, invoices and shipping documents by hand. I built an integration service that synchronises Trendyol, Hepsiburada, N11 and GittiGidiyor with Netsis Accounting in real time: inventory, journal records, orders, e-invoices and e-waybills. It supports multiple databases, uses Hangfire background jobs for peak periods, global error handling and token-based authentication. Manual data entry across all channels was eliminated. Role: Lead developer (Rui Codex) Skills: .NET, Hangfire, REST API, SQL Server, E-commerce integration, E-invoicing, Accounting integration Link: https://www.twine.net/signin

  • Back-End Developer
  • Full Stack Developer
  • Software Engineer
  • +1
Machining process tracking from PLC/SCADA data

A manufacturing facility collected PLC and SCADA data by hand, which left production visibility slow and unreliable. I built a web-based machining process tracking and reporting system that reads industrial equipment over Modbus, UART, CANbus and Ethernet, monitors production in real time, collects operational data automatically and produces detailed reports for production optimisation and maintenance planning. Role: Lead developer (Rui Codex) Skills: ASP.NET Core, SQL Server, PLC, SCADA, Modbus, Industrial IoT, Reporting Link: https://www.twine.net/signin

  • Back-End Developer
  • Full Stack Developer
  • Software Engineer
  • +1
GDPR / KVKK consent management platform

Organisations needed to meet KVKK (Turkish data protection law) and EU GDPR without manual consent tracking. I developed a compliance platform that automates consent and permission flows by e-mail and SMS, tracks every record and manages multiple companies from one place. It integrates IYS (the Turkish message management system) for consent verification and TÜBİTAK timestamping for legal validity, with JWT/cookie hybrid authentication and a responsive admin interface. Role: Lead developer (Rui Codex) Skills: ASP.NET Core, SQL Server, GDPR, JWT, SMS / e-mail integration, Multi-tenant Link: https://www.twine.net/signin

  • Back-End Developer
  • Full Stack Developer
  • Software Engineer
  • +1
Modular web ERP for a growing enterprise

A growing enterprise needed one ERP for every business function with room to integrate external systems. I designed and built Yirmibes Web ERP: a modular web platform covering purchasing, sales, export, finance, cash handling, warehouse, production, reporting and B2B operations. It runs on a multi-database architecture behind an API gateway, with real-time communication, background job processing and advanced reporting (FastReport, DevExpress). The business activates only the modules it needs and scales division by division. Role: Lead developer (Rui Codex) Skills: ASP.NET Core, SQL Server, REST API, API Gateway, ERP, DevExpress, FastReport Link: https://www.twine.net/signin

  • Back-End Developer
  • Full Stack Developer
  • Software Engineer
  • +1
Rui Codex apps & games on Google Play

Rui Codex designs, builds and publishes its own mobile apps and games on Google Play — from utilities and AI tools to casual and idle games — handling store listings, releases, ads and in-app purchases end to end. Role: Publisher (Rui Codex) Skills: Android, Flutter, Firebase, AdMob, In-app purchases, Google Play Link: https://www.twine.net/signin

  • AI Developer
  • Back-End Developer
  • Full Stack Developer
  • +2
EveryTranslate — AI translation SaaS (own product)

EveryTranslate is Rui Codex's own AI translation platform, built from the ground up as a full-stack SaaS: an AI translation engine for 100+ languages, PDF/Word/TXT document translation with preserved formatting, real-time progress updates, a developer REST API, history and favourites, and Free/Daily/Monthly/Yearly subscription plans. It is built with TLS 1.3 end to end and a policy of not storing translated content. Live at everytranslate.com. Role: Founder (Rui Codex product) Skills: ASP.NET Core, AI / LLM APIs, REST API, SaaS, Subscriptions, GDPR, Mobile app Link: https://www.twine.net/signin

  • AI Developer
  • Back-End Developer
  • Full Stack Developer
  • +2

Work experience· 6 roles

Founder & CTO · Rui CodexFeb 2026 – Present · 10 mos

Rui Codex is a Belgian software engineering company (Flemish Region, remote). Custom web applications and APIs in ASP.NET Core, ERP and e-commerce integrations, AI/n8n workflow automation, and the company's own apps and games on Google Play.

Software Development Team Leader · PayologJan 2023 – Sep 2025 · 2 yrs 9 mos

Part-time, remote.

Director of Software Development · Pointix Bilisim TeknolojileriSep 2022 – Jun 2024 · 1 yr 10 mos

Part-time, Istanbul.

CTO · MarQi BlindsFeb 2022 – Present · 4 yrs 10 mos
Senior Software Developer · iXireduOct 2021 – Nov 2022 · 1 yr 2 mos
Full Stack Developer · STAR GRUPOct 2017 – Oct 2021 · 4 yrs 1 mo

Education

Bachelor's degree, Industrial Engineering · National Defence University (Milli Savunma Universitesi), Turkey2011 – 2015

Hire Selman Altinay today

Post a job and invite Selman, or contact them directly. No hidden commission.

Post a job