🎯 Entry-level .NET Backend Developer
💡 Focused on backend architecture, transactional consistency, and domain-centric design
📍 Long An, Vietnam

I am a final-year IT student at Saigon University and currently a Backend Intern at VNPT Long An, working with real production APIs.

My main interest is backend system design — how to structure applications so that business logic remains correct, maintainable, and resilient as complexity grows.

I prefer building correct and long-lived systems over feature-heavy demos, and I actively refactor designs when architectural limitations become clear.

• Languages: C#, SQL
• Frameworks: ASP.NET Core, Entity Framework Core
• Architecture & Patterns:
  • Clean Architecture
  • CQRS
  • Repository & Unit of Work
  • Domain Events (DDD-lite, pragmatic)
• Databases: PostgreSQL, SQL Server
• Authentication & Security:
  • JWT Authentication
  • Role-based Authorization

• Git, GitHub
• Swagger / OpenAPI
• Docker (basic)
• GitHub Actions (basic CI/CD)

Tech: .NET 8, EF Core, PostgreSQL, MediatR, CQRS

TaskMind is a backend-focused project created to rethink architectural decisions made in earlier systems and to explore how backend designs can remain reliable as business complexity increases.

Key focuses:

• Clean Architecture with clear responsibility boundaries
• Domain-centric design (DDD-lite, non-dogmatic)
• Transactional consistency using EF Core and Unit of Work
• Domain Events to decouple side effects from core business logic
• Authentication implemented as a use case, not controller logic

This project prioritizes architectural clarity and correctness over feature breadth.

Includes a small WPF UI as an exploratory MVVM experiment (not part of the core system).

🔗 Repository: https://github.com/toiQS/TaskMind

Tech: ASP.NET Core, EF Core, PostgreSQL, JWT, VNPAY

A real-world backend system developed during my internship, focusing on production-ready APIs and business requirements.

Responsibilities:

• Designed and implemented RESTful APIs for authentication and product management
• Integrated VNPAY payment gateway with secure callback validation
• Optimized database queries and indexing
• Worked within real production constraints and existing systems

🔗 Repository: https://github.com/toiQS/Digital-product-trading-system

• 📧 Email: nguyensieu12112002@gmail.com
• 💼 LinkedIn: Nguyen Quoc Sieu
• 🐙 GitHub: https://github.com/toiQS

This profile focuses on backend architecture and system design thinking, rather than UI or feature quantity.
Projects are selected to demonstrate decision-making, trade-offs, and long-term maintainability.