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Fiverr Pro
English
$
USD
I will net core API bugs, database bottlenecks and optimize performance
Haktan U
About this gig
Are recurring bugs, slow response times, or unexpected 500 errors hurting your .NET application?
I help businesses and developers identify, debug, and resolve critical issues across their ASP.NET Core APIs, backend architectures, and database layers. Whether it is a breaking production bug, poor query performance, or messy code blocking scalability, I deliver clean, robust, and maintainable solutions.
What I Can Help You With
- Bug Fixing & Diagnostics: Resolving 4xx/5xx status code issues, model validation errors, CORS problems, and broken authentication (JWT, Identity, OAuth).
- Database & Query Optimization: Eliminating the N+1 problem, indexing bottlenecks, and tuning slow LINQ / EF Core queries (PostgreSQL, MS SQL).
- Code Refactoring & Clean Architecture: Refactoring legacy logic into clean Service/Repository patterns following SOLID principles.
- Concurrency & Async Fixes: Debugging deadlocks, unhandled thread exceptions, and improper async/await implementations.
- Performance Enhancements: Implementing Redis or in-memory caching and optimizing payload sizes.
- API Documentation & Testing: Providing Postman collections, Swagger configuration, and structured logging.
Tech Stack & Core Ex
Get to know Haktan U
Haktan U
Backend Developer
- FromTurkey
- Member sinceApr 2022
- Avg. response time1 hour
Languages
English, Turkish, Spanish
I am a Backend Developer with 4+ years of experience designing scalable, fault-tolerant core systems using C# and .NET. I specialize in Clean Architecture, microservices, and event-driven systems with Kafka and RabbitMQ. I have a strong track record in payment integrations and database optimization across PostgreSQL and NoSQL environments.
Other Software Development Services I Offer
FAQ
Can you work directly on my GitHub/GitLab repository?
Yes, you can grant me access to your repository (or a dedicated feature branch), and I will submit a clean pull request with detailed commit messages.
What do you need to get started?
A clear description of the bug or performance issue, error logs (or screenshots), and access to the codebase or a reproducible minimal repo.
Will you sign an NDA or respect code confidentiality?
Absolutely. Your intellectual property and code stay strictly private and are deleted from local environments once the order is completed.
