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Fiverr Pro
English
$
USD
I will build a scalable backend API with dotnet 8 csharp and ef core
Renato Ferreira
About this gig
Need a backend that scales without surprises? I build production-ready APIs and microservices in C# and .NET 8 with 20+ years of engineering experience across fintech, audit and high-volume e-commerce, and that runs in production behind my own SaaS products (Chrema, Pyrgos).
What you get is real backend engineering, not tutorial code:
Clean Architecture and DDD layering with Domain, Application and Infrastructure properly separated.
EF Core 8 with real migrations, indexes and query tuning. No N+1 surprises. PostgreSQL, MySQL or SQL Server.
Authentication and authorization done right: JWT bearer, refresh-token rotation, role and permission claims, OAuth2 and OpenID Connect.
Validation with FluentValidation, mapping with AutoMapper, mediation with MediatR (CQRS-ready).
Real automated tests with xUnit covering the critical paths.
Swagger and OpenAPI docs generated and kept in sync with endpoints.
Containerized with Docker. Optional CI CD pipeline and Kubernetes deploy on the Premium tier.
Send a short message before ordering so I can confirm fit, scope and timeline. No surprises.
Get to know Renato Ferreira
Renato Ferreira
Senior Software Engineer
- FromBrazil
- Member sinceMay 2026
Languages
English, Portuguese
I am a Senior Software Engineer with over 20 years of experience in IT, specializing in .NET and C#. I have a solid track record in software engineering, from developing solutions from scratch to modernizing legacy applications with a focus on performance, scalability, and clean architecture.
My Portfolio
FAQ
Do you provide source code and documentation?
Yes. You get the full source code in a private Git repository plus a short README explaining how to run it locally, configure environment variables and deploy. The Premium tier also ships a docker-compose file and a CI CD pipeline.
Can you continue an existing codebase or do you only build from scratch?
Both. I am comfortable continuing existing .NET projects, refactoring legacy code, and integrating new modules into an established codebase. Send me your repo or a representative snippet and I will confirm fit before we start.
Which databases do you support?
PostgreSQL, MySQL and SQL Server are first-class. MongoDB and Redis are supported when the use case fits. I will recommend the right choice based on your domain, scale expectations and existing infrastructure.
How do revisions work?
Revisions cover bug fixes and small adjustments within the agreed scope. Changes that significantly expand the scope (new features, endpoints, integrations) are quoted separately. I aim to ship code that needs few revisions in the first place.
