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$
USD
I will build c sharp dotnet web apps and rest apis
Lucius
About this gig
Build a maintainable C#/.NET web app or REST API with a developer experienced at Microsoft and Tencent.
At Microsoft, I worked on Outlook Search's .NET backend, including .NET Framework-to-.NET Core migration and search latency improvements. At Tencent, I worked on payment-service reliability and failover.
Services:
- C#/.NET and ASP.NET Core web applications
- REST APIs and third-party integrations
- Maintenance and bug fixes for existing .NET applications
Packages cover the page counts and features listed below. API-only work, legacy-system diagnosis, bug fixes and migrations need an agreed scope and custom offer.
Deliverables include source code, relevant comments, testing of agreed functionality, and setup instructions. Hosting, paid services, deployment and ongoing maintenance are excluded unless agreed separately.
Please message me before ordering with your requirements, .NET version, sample data and any errors. I use AI assistance where permitted, review and test deliverables, and respect your confidentiality and AI-use restrictions.
Get to know Lucius
Lucius
C Sharp and Dotnet Developer for APIs and Bug Fixes
- FromChina
- Member sinceSep 2026
Languages
Chinese, English
C#/.NET developer with engineering experience at Microsoft and Tencent. At Microsoft, I worked on Outlook Search's .NET backend, including a large-scale .NET Framework-to-.NET Core migration and search latency improvements. At Tencent, I worked on WeChat Pay backend services, failover and chaos engineering.
I help with C#/.NET bug fixes, legacy-system maintenance, REST APIs and backend development. Python is my second focus; I also work with Java, Go and Rust. Based in China (UTC+8), with clear communication and scoped, tested delivery.
FAQ
What do you need to get started?
Please share your goals, required features, design references, preferred technologies, and any relevant code or API documentation. Use sample data rather than sensitive production data.
Which package should I choose?
Basic covers one page with a simple interactive feature. Standard covers up to 3 pages and one existing API integration. Premium covers up to 5 pages and a small custom backend. Message me if your project does not fit these options.
What does the Premium backend include?
One agreed business workflow, up to 5 custom API endpoints, and up to 3 database tables. Authentication, payments, subscriptions, and complex integrations require a separate quote.
Will I receive the source code?
Yes. All packages include the project source code and setup instructions. Any third-party components remain subject to their respective licenses.
Can you improve an existing application?
Yes. I love it!! I can review existing code, troubleshoot bugs, add features, or integrate APIs. Scope and pricing depend on the codebase and requirements.
What counts as a revision?
A revision is an adjustment within the agreed requirements. Additional features, pages, integrations, or major design changes require a separate quote.
Are hosting and deployment included?
Hosting, domains, paid services, deployment, and ongoing maintenance are not included unless explicitly agreed. Deployment assistance can be quoted separately.
Do you use AI tools?
Yes, where appropriate to accelerate development. I remain responsible for reviewing and testing the deliverables. Please tell me about any AI-use or confidentiality restrictions before we begin.
