You will get build or fix ASP.NET Core Web API for your application
Top Rated
Project details
I will help you build, fix, or improve your ASP.NET Core Web API for scalable, secure, and production-ready applications.
With 18+ years of experience and as a Top Rated freelancer (100% Job Success, 9000+ hours), I specialize in designing high-performance .NET backend systems and APIs used in real-world enterprise environments.
I can help you:
✔ Build new ASP.NET Core APIs from scratch
✔ Fix bugs and production issues
✔ Improve performance and scalability
✔ Integrate third-party APIs (payments, CRM, etc.)
✔ Refactor legacy .NET applications
✔ Implement authentication (JWT, OAuth)
✔ Design and optimize databases
I focus on clean architecture, reliability, and long-term maintainability.
I can also build full-stack solutions using Angular, React, Razor Pages, or Blazor when needed.
If you’re looking for a reliable and experienced .NET developer to deliver high-quality backend solutions, I’m here to help.
With 18+ years of experience and as a Top Rated freelancer (100% Job Success, 9000+ hours), I specialize in designing high-performance .NET backend systems and APIs used in real-world enterprise environments.
I can help you:
✔ Build new ASP.NET Core APIs from scratch
✔ Fix bugs and production issues
✔ Improve performance and scalability
✔ Integrate third-party APIs (payments, CRM, etc.)
✔ Refactor legacy .NET applications
✔ Implement authentication (JWT, OAuth)
✔ Design and optimize databases
I focus on clean architecture, reliability, and long-term maintainability.
I can also build full-stack solutions using Angular, React, Razor Pages, or Blazor when needed.
If you’re looking for a reliable and experienced .NET developer to deliver high-quality backend solutions, I’m here to help.
Programming Languages
ASP.NET, C#Coding Expertise
Cross Browser & Device Compatibility, Localization, Performance OptimizationWhat's included
| Service Tiers |
Starter
$75
|
Standard
$250
|
Advanced
$600
|
|---|---|---|---|
| Delivery Time | 1 day | 2 days | 7 days |
Number of Revisions | 1 | 2 | 3 |
Number of Pages | 1 | 2 | 3 |
Design Customization | |||
Content Upload | - | - | |
Responsive Design | - | ||
Source Code |
49 reviews
(46)
(2)
(0)
(1)
(0)
This project doesn't have any reviews.
JM
Jaliyl M.
Jun 3, 2026
Senior .NET Backend Architect
Highly recommend! The work was excellent. We had to close the contract only because my side wasn't fully prepped to continue, but I will definitely rehire him once the project is ready to kick off again. Great experience overall.
JI
Joe I.
Apr 10, 2026
Full Stack Developer
Great developer! I've hired Yasir before and would hire him again!
EM
Elie M.
Jan 21, 2026
Full stack dev for e-commerce project
Yasir is very skilled in software development and architecture, a good communicator, and detail-oriented. It's been a pleasure to work with Yasir, and I highly recommend him.
PS
Prem S.
Jun 16, 2025
Azure backend
Good skills with Azure, .Net. Helped to build API's, and to bring suggestions for best practices. Will work with Yasir again!
JI
Joe I.
Sep 11, 2024
.NET API Developer in Azure
Yasir did a great job jumping in and getting started right away. It was easy to talk with him about complex concepts. He reviewed the existing coding patterns, implemented new work following those patterns, and was open to feedback and suggestions during code reviews.
He successfully created integrations with Stripe and RevenueCat, demonstrating his ability to handle complex integrations. Additionally, he took the initiative to learn how to make updates to our Terraform automation and GitHub Actions pipelines so that he could assist further. Yasir worked with various Azure services, including Cosmos DB, SQL, and Azure Container Apps, effectively integrating these into the project. He received feedback on pull requests professionally and showed a genuine interest in implementing them correctly.
I would definitely hire him again.
He successfully created integrations with Stripe and RevenueCat, demonstrating his ability to handle complex integrations. Additionally, he took the initiative to learn how to make updates to our Terraform automation and GitHub Actions pipelines so that he could assist further. Yasir worked with various Azure services, including Cosmos DB, SQL, and Azure Container Apps, effectively integrating these into the project. He received feedback on pull requests professionally and showed a genuine interest in implementing them correctly.
I would definitely hire him again.
About Yasir
Full Stack Developer | .NET | C# | Azure | Angular | React | SaaS App
100%
Job Success
Rawalpindi, Pakistan - 7:54 am local time
With 18+ years of hands-on experience across the .NET ecosystem, I specialize in both new development and legacy modernization — upgrading older .NET Framework, WebForms, and WinForms applications to modern, cloud-ready architectures using ASP.NET Core, Angular, React, and Azure.
✔ 18+ years of enterprise software development
✔ 60+ projects delivered | 9000+ hours worked on Upwork
✔ Azure Certified (Developer Associate + Cosmos DB Specialty)
✔ Trusted by international clients including FDM, Danx, and Atea
✔ AI-assisted development (Claude/Copilot) for faster delivery with strong test coverage
⭐ WHAT CLIENTS SAY
✔ "Yasir did a great job jumping in and getting started right away... open to feedback and suggestions during code reviews."
✔ "Yasir joined us when we needed a developer immediately, he quickly understands the requirements and did quality work."
✔ "Very skilled in software development and architecture, a good communicator... a pleasure to work with."
💡 HOW I CAN HELP YOU
✔ Build scalable ASP.NET Core Web APIs & microservices
✔ Design and deploy secure Azure cloud solutions (Functions, App Services, Cosmos DB)
✔ Develop full-stack apps with Angular, React, Next.js, or Blazor
✔ Upgrade legacy .NET Framework / Web Forms apps to modern architecture
✔ Fix critical production issues and improve performance
✔ Integrate third-party APIs and automate workflows with AI tools
🛠 CORE TECH STACK
✔ C#, ASP.NET Core, .NET Web APIs, .NET 8/9
✔ .Net Framework 2.0 / 3.0 / 3.5 / 4.0 / 4.5 / 4.8
✔ WPF / Windows App
✔ Azure (Functions, App Services, Storage, Cosmos DB, Service Bus, Event Grid, DevOps/CI-CD)
✔ Angular, React, Next.js, Blazor (WASM & Server), TypeScript
✔ SQL Server, Entity Framework, REST APIs
✔ Git, Agile, AI-assisted development workflows
✔ Telerik Reports
☁️ CERTIFICATIONS
✔ Microsoft Certified: Azure Developer Associate
✔ Microsoft Certified: Azure Fundamentals
✔ Microsoft Certified: Azure Cosmos DB Developer Specialty
I am available to start quickly and can work independently or embed with your existing team. Whether it's a new build, a legacy upgrade, or an urgent fix, invite me to your job and let's get started.
Steps for completing your project
After purchasing the project, send requirements so Yasir can start the project.
Delivery time starts when Yasir receives requirements from you.
Yasir works on your project following the steps below.
Revisions may occur after the delivery date.
Requirement Analysis
Understand your needs, review requirements, and clarify scope before starting.
API Design & Development
Test endpoints, fix issues, and ensure performance, security, and reliability.