You will get Full-stack .NET + React web + React Native mobile app with PostgreSQL/MSSQL
Project details
You will get a complete full-stack application delivered by a senior Software Architect with 30 years of engineering experience, accelerated by an AI-assisted workflow. I pair human architectural judgment with modern AI coding tools (Claude, Cursor, GitHub Copilot) to ship production-grade code faster, while keeping every line reviewed, tested, and aligned with best practices. The stack is .NET (C#, ASP.NET Core, REST APIs, Entity Framework), React (JavaScript/TypeScript) for web, and React Native for iOS and Android. The database is PostgreSQL or MS SQL Server, with JWT/OAuth security, CI/CD, and clean modular architecture. You get a working backend, web app, and mobile app, plus documentation, deployment, and a senior engineer accountable for the result, not just AI-generated snippets.
Programming Languages
JavaScript, ASP.NET, C#Coding Expertise
PSD to HTML, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$1,500
|
Standard
$5,000
|
Advanced
$10,000
|
|---|---|---|---|
| Delivery Time | 14 days | 30 days | 60 days |
Number of Revisions | 2 | 4 | 9 |
Design Customization | - | ||
Content Upload | - | ||
Responsive Design | |||
Source Code |
Frequently asked questions
About Antnan
Software Architect | AI Agents, FinTech & Open Banking
Istanbul, Turkey - 2:56 am local time
What I do best:
• AI Agents & LLM applications — production agentic systems with OpenAI, Anthropic Claude, Computer Use, RAG, tool calling, multi-agent orchestration
• FinTech & Payments — payment gateways, POS reporting, direct debit, bulk fund transfer, B2B/B2C/B2B2C payment collection
• Open Banking — UK OBIE ASPSP and Turkey OHVPS AISP/PISP API infrastructure, account aggregation, PSD2-aligned flows
• Enterprise Architecture — microservices, event-driven design, high availability, monolith-to-microservices transformation
• Crypto & Trading Infrastructure — backend architecture for high-frequency order matching, wallet management, exchange integrations
• Mobile — cross-platform apps with React Native for Android and iOS
Currently:
- Software Architect at Machinarium — backend architecture for a crypto currency trading platform (Stablex)
- Software Engineering Manager at Quality Museum — building AI agents and agentic AI systems (Uxer)
Selected achievements:
- Led the development of one of Turkey's largest online payment collection platforms (Netahsilat by Finrota) handling B2B, B2C, and B2B2C transactions for thousands of merchants
- Designed Open Banking API infrastructure for both UK (OBIE ASPSP) and Turkey (OHVPS AISP/PISP)
- Built enterprise products: Netekstre (multi-bank cash management), Posrapor (POS reporting), E-DBS (direct debit), TÖS (bulk fund transfer)
- Led PCI DSS certification and full monolith-to-microservices transformation as CTO at Eçözüm (2011–2022)
- Developed mobile cell device monitoring at Nokia Siemens Networks (Düsseldorf)
Technical stack:
C# • .NET Core • ASP.NET MVC • React • React Native • Node.js • PostgreSQL • MS SQL Server • MongoDB • Redis • RabbitMQ • Apache Kafka • SignalR • Hangfire • ELK Stack • Docker • Kubernetes • Microservices • REST and GraphQL APIs
AI and Automation:
OpenAI API • Anthropic Claude • Claude Code • Computer Use • Agentic AI • LLM integration • Prompt Engineering • RAG • Vector DBs • AI-assisted testing • RPA
Why clients hire me:
- 30+ years of real-world software experience, including CTO and engineering leadership
- Deep regulated-industry expertise: PCI DSS, PSD2, KVKK/GDPR, BDDK
- Strong communicator — fluent in English, Turkish, and German (plus conversational Greek)
- I take ownership: from architecture and discovery to delivery, scaling, and team mentoring
- Comfortable working solo as a senior architect or leading distributed engineering teams
Education:
BSc Computer Engineering — Bosphorus University
MSc IT Security — Ruhr University Bochum
Available for long-term contracts and high-impact, short engagements involving AI agent development, FinTech platforms, Open Banking, crypto trading systems, and .NET/React enterprise solutions. Let's talk about your project — I respond within a few hours on Upwork.
Steps for completing your project
After purchasing the project, send requirements so Antnan can start the project.
Delivery time starts when Antnan receives requirements from you.
Antnan works on your project following the steps below.
Revisions may occur after the delivery date.
Discovery & requirements
Working session to capture features, user roles, integrations, performance and security needs, and to pick PostgreSQL vs. MS SQL Server based on your hosting and workload.
Architecture & data model
Design of the .NET backend (ASP.NET Core APIs, services, microservices if needed), database schema, auth model (JWT/OAuth), and shared API contracts used by web and mobile.