You will get your ASP.NET Core Web API bug diagnosed and fixed
Project details
Is your ASP.NET Core Web API returning 500 errors, throwing exceptions, producing incorrect data, or failing during database operations?
I will diagnose and fix clearly scoped backend issues in ASP.NET Core applications using C#, .NET 8/.NET Core, SQL Server, Entity Framework Core, Dapper, REST APIs, stored procedures, and database transactions.
Depending on the selected package, I can investigate controller, service, data-access, and database layers; apply a focused fix; add basic tests; and provide concise technical notes explaining the root cause and changes made.
Typical issues include null-reference errors, validation and mapping bugs, incorrect business logic, EF Core or Dapper data-access problems, SQL query or stored-procedure issues, authentication or authorization errors, and transaction failures.
I avoid unnecessary rewrites and keep changes limited to the agreed scope. Please contact me before ordering if the issue spans multiple systems, requires frontend work, production server administration, or a major architectural redesign.
I will diagnose and fix clearly scoped backend issues in ASP.NET Core applications using C#, .NET 8/.NET Core, SQL Server, Entity Framework Core, Dapper, REST APIs, stored procedures, and database transactions.
Depending on the selected package, I can investigate controller, service, data-access, and database layers; apply a focused fix; add basic tests; and provide concise technical notes explaining the root cause and changes made.
Typical issues include null-reference errors, validation and mapping bugs, incorrect business logic, EF Core or Dapper data-access problems, SQL query or stored-procedure issues, authentication or authorization errors, and transaction failures.
I avoid unnecessary rewrites and keep changes limited to the agreed scope. Please contact me before ordering if the issue spans multiple systems, requires frontend work, production server administration, or a major architectural redesign.
Programming Languages
ASP.NET, C#Coding Expertise
Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$59
|
Standard
$129
|
Advanced
$249
|
|---|---|---|---|
| Delivery Time | 2 days | 3 days | 5 days |
Number of Revisions | 1 | 1 | 2 |
Bug Investigation | |||
Fix Documentation | - | ||
Detailed Code Comments | - | - |
Frequently asked questions
About Nguyen
ASP.NET Core Developer | SQL Server & API Fixes
Hanoi, Vietnam - 3:11 am local time
I’m a .NET backend developer with commercial experience maintaining a multi-tenant business system using C#, .NET 8, ASP.NET Core Web API, SQL Server, Dapper, Entity Framework Core, stored procedures, and database transactions.
I can help with:
• Debugging ASP.NET Core API errors and 500 responses
• Building or extending REST API endpoints
• Optimizing SQL Server queries and stored procedures
• Fixing Dapper or Entity Framework Core data-access issues
• Refactoring focused backend components
• Assisting with authentication, validation, and backend documentation
My recent work includes REST API development, stored-procedure maintenance, multi-tenant data handling, and transaction-sensitive workflows for access control and payment records.
I focus on clearly scoped backend tasks. You will receive focused changes, realistic estimates, regular progress updates, and a clear explanation of the solution.
Send me the task description, error log, stack trace, or SQL query, and I will review the scope and propose the next steps.
Steps for completing your project
After purchasing the project, send requirements so Nguyen can start the project.
Delivery time starts when Nguyen receives requirements from you.
Nguyen works on your project following the steps below.
Revisions may occur after the delivery date.
Review and reproduce the issue
I review the supplied code, logs, setup instructions, and expected behavior. I then reproduce the issue and confirm that it fits the selected package.
Diagnose the root cause
I trace the request through the controller, service, data-access, and database layers to identify the actual cause rather than applying an unsupported workaround.