Sunil S.

Full Stack .NET Developer with 25+ years in C#, SQL Server, VB6, and Access. I build custom software, fix legacy systems, automate Excel reports, and optimize databases. 100+ 5-star projects Need a .NET app built? An Access database fixed? Excel automated? Power-BI Dashboard? SSRS Report? I do it all – reliably. 25+ yrs, 100+ 5-star projects (Guru). Let's talk Your Trusted Partner for Business Software That Just Works I've completed over 100 projects on another platform with perfect 5-star ratings. I'm new to Upwork, but not to freelancing. For over 25 years as a Full Stack .NET Developer and Software Architect, I've helped businesses like yours modernize operations, solve complex data problems, and automate tedious tasks. I don't just write C# code; I build reliable, user-friendly tools using ASP.NET Core, WinForms, WPF, and SQL Server backends that become the backbone of your daily workflow. As a seasoned developer specializing in the Microsoft ecosystem, I offer a unique blend of modern application development and deep expertise in maintaining legacy systems built in VB6 and older Access versions. My focus is on delivering clear value: saving you time, reducing errors, and giving you control over your data. What you get when you hire me: I deliver more than just working code—I deliver peace of mind. I build and maintain advanced .NET applications (C#, ASP.NET Core, .NET Framework) with scalable backend architectures, clean REST APIs, and heavily optimized SQL Server databases using Entity Framework, stored procedures, and performance tuning. I have deep experience integrating these systems with enterprise platforms like ERPs, CRMs, e-commerce engines, OMS, payment gateways, and shipping APIs. On the technical side, I excel at auditing messy codebases, refactoring legacy code into maintainable systems, debugging the most stubborn production issues, implementing secure authentication/authorization, and reviewing code to recommend real architectural improvements. I write clean, well-documented code and collaborate seamlessly with project managers, QA, front-end developers, and technical leadership. On the consulting side, I work entirely independently, communicate technical decisions in plain business language, and give you an honest, no-surprises assessment of risks, timeframes, and blockers from day one. I document everything, join calls whenever needed, and treat your timeline as seriously as my reputation. How I Can Solve Your Business Challenges: · Modern Desktop & Web Applications: Building robust, scalable systems in C# .NET (WinForms, WPF) with SQL Server backends for inventory, ERP, and custom business logic. · Database Design & Optimization: Expert in SQL Server and Microsoft Access. I specialize in converting outdated Access databases, fixing performance issues, and designing efficient, secure data structures. · Office Automation & Integration: Creating powerful macros and add-ins for Excel, Word, and Outlook to automate reports, generate documents, and streamline communication. · Legacy System Support & Troubleshooting: A proven expert in Visual Basic 6 (VB6) and older Access versions. I can take over undocumented, complex systems, reverse-engineer them, and provide stable, long-term support. · API Integration & Data Consolidation: Connecting your software to other services, pulling data from various sources (APIs, Excel, CSV), and creating a single source of truth. · Custom Reports in Intuit QuickBooks via ODBC connection, execute queries, retrieve data/transactions based on user defined criteria. Connect to QuickBooks via its API to post vouchers through custom desktop/web applications. Import/Export from QuickBooks. Why Clients Keep Coming Back: · Deep Domain Knowledge: I've built solutions for construction, manufacturing, legal, banking, and warehousing. I understand your industry's unique challenges. · Clear Communication: I translate technical jargon into plain English. You'll always know the plan, the progress, and the outcome. · Low-Risk, High-Value Projects: I believe in starting with a clear assessment and a fixed-price roadmap. You'll know exactly what you're getting before any major work begins. Let's build something great together. Send me an invitation, and let's discuss how I can bring reliability and expertise to your project. The difference between a cheap developer and a senior architect often isn’t in the features you can see, but in the catastrophes you never see. While I'm newer to Upwork, I've maintained a 100% success rate with 50+ projects over 10 years on Guru dot com. You can see my extensive portfolio and client reviews there to verify my track record there. My profile ID is 'sunil-2060'