Hire the Best .NET Core Developers in Hanoi, VN

I’m a developer experienced in building websites for small and medium-sized businesses. Whether you’re trying to win work, list your services, or create a new online store, I can help. Knows HTML, CSS3, React, Nextjs, Angular, Vue, Nodejs, C#, PHP, Laravel and ASP.NET Full project management from start to finish Regular communication is important to me, so let’s keep in touch.

With over 3 years of experience in software development, I’m a developer experienced in building websites for small and medium-sized businesses. - ASP .NET, .NET Core, .NET Framework - VueJS, Angular - MongoDB, MySQL, PostgresDB, Kafka, RabbitMQ - Docker, K8s, Jenkins

🏆 Upwork Top Rated Plus Talent (July 2023 – Present) 🏆 Upwork Top Rated Talent (Feb 2022 – July 2023) ⚡ $100K+ earned on Upwork within 4 years I specialize in optimizing, building, and scaling Zoho solutions and automation systems that significantly enhance business performance. As a leading Zoho developer in Vietnam with strong C# expertise, I help businesses streamline operations, improve data accuracy, and unlock growth through well-architected systems and intelligent automation. 🔹 Zoho Solutions & Business Automation 1. Design and implement end-to-end Zoho One ecosystems (CRM, Books, Inventory, Projects) 2. Build advanced customizations using Deluge, Client Scripts, and Widgets 3. Develop seamless integrations with third-party platforms (Stripe, Xero, Twilio, RingCentral, Shipping APIs) 4. Engineer robust workflows, validation logic, and automation to ensure efficiency and data integrity 🔹 AI & Intelligent Automation 1. Integrate LLMs (ChatGPT, Gemini) into business workflows 2. Automate document processing (OCR) and client communication 3. Convert unstructured data (PDFs, emails) into structured, actionable insights 🔹 Full-Stack Development (C# / .NET) 1. Develop scalable enterprise applications using ASP.NET Core and modern .NET 2. Apply SOLID principles and design patterns (MVC, DI, Repository) 3. Design efficient database architectures with Entity Framework Core and SQL optimization 4. Build clean, high-contrast UI with React and Ant Design 5. Deploy and manage solutions on Azure and AWS My goal is simple: build systems that don’t just work — but actively support and accelerate your business growth.

I am a web developer with experience in developing software for small and medium-sized businesses, along with VoIP and WebRTC systems. If you need to develop a website using technologies like Spring, .NET, Node.js, or implement VoIP systems for voice communication or customer survey campaigns, I can help.

I’m a Senior .NET Developer combined with a Business Analyst mindset, with 10+ years of experience delivering and rescuing business-critical systems. I don’t just develop features — I analyze business workflows, fix system bottlenecks, and deliver scalable solutions that actually improve operations. In addition, I bring strong UI/UX implementation skills, allowing me to turn designs into pixel-perfect, production-ready interfaces — ensuring both performance and user experience. 🏆 Top Rated Freelancer 🏆 100% Job Success Score 💰 $10,000+ Earned 🚀 What I Specialize In 🔹 ERP / CRM / Business Systems Development Design and build systems for Sales, HRM, Warehouse, Manufacturing, Fleet Management Translate business requirements into scalable technical solutions 🔹 Legacy System Modernization (.NET) Upgrade old systems (.NET MVC, WebForms) → .NET Core / Blazor Refactor messy codebases into maintainable architectures Improve system performance, stability, and scalability 🔹 System Performance Optimization Fix slow systems (database queries, API latency, UI rendering) Optimize SQL, backend logic, and frontend performance 🔹 Pixel-Perfect UI Development (Figma / Adobe → Code) Convert Figma / Adobe XD / Photoshop designs into responsive HTML/CSS Ensure pixel-perfect accuracy across devices and browsers Implement UI using Blazor, DevExpress, Telerik 🔹 Business Analysis + Technical Execution Analyze workflows and suggest better system design Reduce operational inefficiencies through smart automation 💡 Why Clients Hire Me I think like a business owner, not just a developer I can quickly understand complex legacy systems and take ownership I proactively identify risks, bottlenecks, and better approaches I communicate clearly and provide regular progress updates 🧠 Tech Stack Backend: C#, .NET Core, ASP.NET MVC, Web API, Entity Framework Frontend: Blazor, HTML, CSS, JavaScript, Bootstrap, jQuery UI Frameworks: DevExpress, Telerik (Kendo UI), Syncfusion Database & Data: SQL Server, PL/SQL, OLAP, MDX Other: Python, ETL, Power BI, Excel, .NET MAUI 🎯 Productized Services (Fixed Scope – High Value) 💼 ERP / CRM System Audit – from $200 - Review architecture, database, and workflows - Identify bottlenecks & risks - Provide actionable improvement plan ⚡ Fix Slow .NET System – from $300 - Analyze performance issues (SQL / API / UI) - Optimize response time and system stability - Deliver measurable improvements 🔧 Legacy System Upgrade (.NET MVC → .NET Core / Blazor) - Codebase assessment - Migration strategy - Step-by-step modernization plan 📊 Database & Query Optimization – from $150 - Analyze slow queries - Optimize indexes and execution plans - Improve overall system performance 📌 Best Fit Clients - Companies running old .NET systems with performance issues - Businesses needing ERP / HRM systems built or improved - Founders who want a developer that understands business, not just code 💬 Let’s Work Together If your system is slow, hard to maintain, or no longer fits your business — I can help you analyze, fix, and upgrade it efficiently.

Hi, I'm Jack (Tran Van Diep). I help businesses build AI-powered systems, intelligent agents, and scalable software products that automate operations, reduce costs, and accelerate growth. Although I am new to Upwork, I am not new to software development. I bring over 15 years of hands-on experience building mobile applications, backend systems, SaaS platforms, and enterprise solutions. Today, my primary focus is helping startups and businesses adopt AI through Agentic AI, workflow automation, and custom AI-powered applications. I am also the founder of a software development company in Vietnam, where I have led engineering teams, delivered production systems, and helped clients transform business ideas into successful digital products. I joined Upwork to build long-term relationships with international clients and expand my AI and software development services globally. 🚀 AI Agents & Agentic AI (Primary Focus) I design and build intelligent AI systems that can reason, make decisions, interact with tools, and automate business workflows. • AI Agents & Multi-Agent Systems • Agentic AI Applications • LangChain & LangGraph • Retrieval-Augmented Generation (RAG) • Knowledge Base AI Assistants • AI Customer Support Systems • Workflow Automation & AI Orchestration • Claude, ChatGPT, Gemini & Open-Source LLM Integrations • Internal Enterprise AI Assistants • AI-Powered SaaS Platforms ✔ Mobile Development • Android (Java, Kotlin, Jetpack Compose) • iOS (Swift, SwiftUI) • Flutter & React Native ✔ Backend & System Architecture • Scalable Microservices Architecture • REST APIs & Platform Development • Event-Driven Systems • Real-Time Communication Platforms • WebSocket Infrastructure • Cloud-Native Applications • Database Design & Optimization What I bring to your project: • 15+ years of professional software development experience • Strong AI implementation and system architecture expertise • Ability to transform business processes into AI-driven workflows • Clean, maintainable, production-ready code • Experience leading engineering teams and delivering complex products • Clear communication and transparent collaboration • A long-term technology partner mindset Projects I can help you build: • AI Agents for Business Automation • AI Customer Support & Knowledge Assistants • AI Workflow Automation Platforms • Internal Company AI Tools • AI-Powered SaaS Products • Real-Time Communication Platforms • Mobile Applications • Enterprise Systems • Custom Software Solutions I understand that trust is important when hiring a freelancer, especially someone who is new to Upwork. That is why I focus on delivering measurable business outcomes, maintaining clear communication, and building long-term partnerships with every client. If you are looking for a developer who can contribute not only as an engineer but also as an AI solutions architect and technical partner, I would be happy to discuss your project. Let's build intelligent systems that create real business value.