You will get .NET Developer | Full Stack Developer | API Integration | C#
Top Rated
Project details
You will get a .NET Developer and Full Stack Developer who designs, builds, and integrates REST APIs — connecting your C# .NET Core backend to Stripe, SendGrid, Twilio, AWS, PayPal, or any third-party service your product depends on.
As a Senior .NET Developer and Full Stack Developer I have delivered API integrations for SaaS, FinTech, and HealthTech platforms — clean service layers, error handling, retry logic, and full test coverage on ASP.NET Core and C# .NET backends.
What you get:
• .NET Developer API build: ASP.NET Core REST API, C# service layer, auth and RBAC
• Full Stack Developer wiring: React or Angular frontend connected to the new API layer
• Integration delivery: Postman collection, integration tests, and written handoff spec
.NET Developer, .NET Developer, .NET Developer, Full Stack Developer, Full Stack Developer, Full Stack Developer, C# Developer, C# .NET Developer, Senior .NET Developer, .NET Core Developer, .NET Full Stack Developer, Full Stack Developer React, JavaScript Fullstack, Senior Fullstack Developer, Fullstack Web Developer, Web Developer, .NET Core React, .NET Core Angular, C# .NET Core, C# Angular, React Developer, Python Developer.
As a Senior .NET Developer and Full Stack Developer I have delivered API integrations for SaaS, FinTech, and HealthTech platforms — clean service layers, error handling, retry logic, and full test coverage on ASP.NET Core and C# .NET backends.
What you get:
• .NET Developer API build: ASP.NET Core REST API, C# service layer, auth and RBAC
• Full Stack Developer wiring: React or Angular frontend connected to the new API layer
• Integration delivery: Postman collection, integration tests, and written handoff spec
.NET Developer, .NET Developer, .NET Developer, Full Stack Developer, Full Stack Developer, Full Stack Developer, C# Developer, C# .NET Developer, Senior .NET Developer, .NET Core Developer, .NET Full Stack Developer, Full Stack Developer React, JavaScript Fullstack, Senior Fullstack Developer, Fullstack Web Developer, Web Developer, .NET Core React, .NET Core Angular, C# .NET Core, C# Angular, React Developer, Python Developer.
Programming Languages
Python, ASP.NET, C#Coding Expertise
Cross Browser & Device Compatibility, Performance Optimization, DesignWhat's included
| Service Tiers |
Starter
$49
|
Standard
$5,000
|
Advanced
$10,000
|
|---|---|---|---|
| Delivery Time | 2 days | 7 days | 21 days |
Number of Revisions | 0 | 1 | 2 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - | - | - |
Frequently asked questions
13 reviews
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DG
Dmitry G.
Jul 9, 2026
.NET Developer / Full Stack Developer Needed for Auth Session Issues
Quickly grasped a complex problem, proposed a solid technical solution, and delivered results without unnecessary delays or back-and-forth.
OS
Oleksandr S.
May 22, 2026
Full Stack Developer & .NET Developer help with API Integration issues
Really impressed with Daria's expertise. She spotted the root cause of our API issues within the first 30 minutes and explained everything clearly. Highly recommend for any .NET or Full Stack Developer consultation
OK
Olha K.
Feb 11, 2026
Full Stack .NET Developer Needed to Help With Payment Integration
Daria did a great job helping us fix our Stripe integration in a .NET app. She quickly found why webhooks weren’t updating the order status and guided us through a clean solution. Clear communication, fast turnaround, and very easy to work with. Would definitely hire again.
BL
Bartosz L.
Jun 2, 2023
.NET Developer needed to develop Blazor application (PART TIME)
Daria is great for her excellent work, communication, availability, and technical skills in .NET. Her coding proficiency, clear communication, prompt availability, and strong technical abilities have been instrumental in the success of your project. She is a valuable asset to your team.
SW
Stuart W.
Apr 3, 2021
.Net Full stack developer
Dari was easy to communicate with and an excellent and talented developer
About Daria
.NET Developer | Full Stack Developer | C# Developer | Angular Blazor
100%
Job Success
Zaporozhye, Ukraine - 1:58 am local time
As a .NET Developer, I migrated 3 legacy monoliths to .NET Core microservices, +70% deployment speed
💥 Recent win — as a Full Stack Developer and C# Developer, I rebuilt a logistics platform using .NET Core, Angular and MySQL, cutting order processing time by 55% and lifting client retention by 22%.
🟢 Most business platforms are slow, hard to scale and expensive to maintain. With 8+ years as a .NET Developer, C# Developer and Full Stack Developer, I architect scalable web developer solutions on .NET, Angular, React and Python stacks that turn technical debt into growth 🟢
📩 Send me your project brief — I'll reply with a free technical review within a few hours, covering architecture, performance and security.
⭐️⭐️⭐️⭐️⭐️ "She's an outstanding .NET Developer and Full Stack Developer. Reliable, communicative, and delivers clean, production-ready C# code every time."
🎯 WHY CLIENTS CHOOSE ME AS A FULL STACK DEVELOPER
I'm a Full Stack Developer, .NET Developer and C# Developer with full-cycle ownership — from database architecture and API design to pixel-perfect frontends. As a C# Developer, I write clean, testable code following SOLID principles, and as a Full Stack Developer I make sure the entire product, not just one layer, actually works for your users.
✔️ .NET Core & C# — as a .NET Developer and C# Developer: scalable ASP.NET Core APIs, background services, .NET MAUI apps ✔️ Frontend — React, Angular, Vue.js, jQuery, built for speed and clean UX ✔️ Full Stack Development — as a Full Stack Developer, connecting .NET, Node.js and Python backends to JavaScript frontends ✔️ Web Developer Services — as a web developer, WordPress, Laravel and PHP sites alongside custom .NET apps ✔️ Database Architecture — MySQL, SQL Server, API Integration for data-heavy systems ✔️ Cloud & DevOps — Azure, AWS, Docker, CI/CD, supporting .net full stack developer and full stack developer react deployments
📊 RESULTS THAT SPEAK
🔶 Fintech Platform: as a .NET Developer and C# Developer, -60% transaction errors, 99.9% uptime via a full .NET Core rebuild 🔶 E-commerce Marketplace: as a Full Stack Developer, React + .NET Core APIs, +28% checkout conversion, 3x page load speed 🔶 Healthcare SaaS: as a senior .net developer, HIPAA-compliant rebuild, -40% manual admin work
⚙️ TECH STACK — WHAT I ACTUALLY BUILD
✔️ As a C# Developer, I build backend services and APIs in C#, .NET and .NET Core ✔️ As a .NET Developer, I build enterprise systems on .NET Framework, deploy cross-platform apps with .NET MAUI, and ship RESTful APIs with ASP.NET ✔️ As a Full Stack Developer, I build frontend interfaces in React, Angular, Vue.js and JavaScript, and add type safety with TypeScript ✔️ As a Full Stack Developer, I build backend logic in Node.js and Python, and CMS-driven sites in PHP, Laravel and WordPress ✔️ As a web developer, I build responsive layouts with HTML5, CSS 3, Bootstrap and jQuery ✔️ As a Full Stack Developer, I build and manage data layers in MySQL and SQL Server
💼 EVERY PROJECT AS A FULL STACK DEVELOPER INCLUDES
▪️ Clean, well-documented C# and .NET code with automated testing ▪️ Direct communication, just a senior C# Developer / .NET Developer working on your project ▪️ Ongoing support after launch as your long-term Full Stack Developer and .NET Developer partner
🏭 INDUSTRIES
Fintech · Healthcare · E-commerce · Logistics · SaaS · Real Estate · EdTech
🔎 ALSO EXPERIENCED AS — EVERY ROLE, PROVEN TWICE
✔️ As a react developer, I build interactive dashboards for SaaS platforms. As a react developer, I also rebuild legacy UIs for speed and scale. ✔️ As a python developer, I build backend APIs and automation scripts. As a python developer, I also ship data-processing pipelines for reporting tools. ✔️ As a java developer, I build backend modules for enterprise systems. As a java developer, I also debug and refactor legacy Java codebases. ✔️ As a blockchain developer, I build and audit smart contracts. As a blockchain developer, I also integrate wallet and token logic into existing platforms. ✔️ As a mobile app developer, I build cross-platform releases for iOS and Android. As a mobile app developer, I also ship post-launch updates and bug fixes. deployment pipelines.
🚀 LOOKING FOR A RELIABLE FULL STACK DEVELOPER OR .NET DEVELOPER?
👉 Share your project details and I'll reply with a clear technical plan. Hire a proven .NET Developer, C# Developer and Full Stack Developer who ships secure, scalable, production-ready software — on time, every time.
📅 Last updated: 21.08.2026
Steps for completing your project
After purchasing the project, send requirements so Daria can start the project.
Delivery time starts when Daria receives requirements from you.
Daria works on your project following the steps below.
Revisions may occur after the delivery date.
API scope & contract definition
I review your integration requirements, map the endpoint structure, define data contracts, and lock the scope before coding.
API development & integration
I build the .NET Core service layer, connect the third-party API, handle errors and retries, and wire the frontend if needed.