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$
USD
I will fix asp net core web API bugs, authentication and 500 errors
Shinji T
About this gig
Is your ASP NET Core Web API returning 500 errors, failing authentication, or behaving unexpectedly?
I will investigate and fix bugs in your C# backend, REST API, Entity Framework Core, or SQL Server integration.
I can help with:
ASP NET Core Web API errors
HTTP 400, 401, 403, 404, and 500 errors
Authentication and authorization issues
Entity Framework Core and SQL Server bugs
Dependency injection or configuration errors
API integration and JSON serialization
Backend performance issues
You will receive:
Root-cause investigation
Clean, focused code fix
Verification of the reported issue
Brief fix documentation
Confidential handling of your code
Please contact me before ordering with:
1. A short issue description
2. Error messages or logs
3. Steps to reproduce the problem
4. Your .NET version
5. Source code access or a minimal example
Revisions cover the originally reported issue only. New bugs, features, deployment, or unrelated changes require a separate order or custom offer.
Send me the details, and I will help you choose the correct package.
Get to know Shinji T
Shinji T
Native Japanese QA Tester, HR SaaS and ASP NET Developer
- FromJapan
- Member sinceJun 2026
- Avg. response time1 hour
Languages
Japanese, English
I am a native Japanese .NET developer with 10+ years of experience in HR, payroll, accounting, attendance, and back-office systems.
I help global clients review HR SaaS products for Japanese users and fix ASP.NET Core Web API, C#, Entity Framework Core, and SQL Server issues.
My experience includes approval workflows, database integration, localization, debugging, and root-cause analysis. I provide clear English communication, practical recommendations, focused fixes, and transparent scope.
Message me to discuss your product or technical issue before ordering.
My Portfolio
FAQ
What do you need before I place an order?
Please send a brief issue description, error messages or logs, reproduction steps, your .NET version, and relevant code. Contact me first so I can confirm the scope and correct package.
Can you fix any ASP NET Core bug?
I handle Web API, authentication, dependency injection, Entity Framework Core, SQL Server, configuration, serialization, and backend logic issues. I will review the problem before confirming the order.
Do you need access to my full source code?
Not always. A minimal reproducible example may be enough. If broader access is required, please remove passwords, API keys, connection strings, and production secrets before sharing files.
Does the service include deployment?
Deployment is not included by default. The packages cover investigation, code fixes, and verification in the provided environment. Deployment can be discussed separately after reviewing your setup.
What is included in a revision?
A revision covers the originally reported issue if the delivered fix does not work as agreed. New bugs, features, environment changes, or unrelated requests require a separate order or custom offer.
