Hire senior C# developers for .NET services and apps
Senior C# engineers who build and modernize ASP.NET Core services, Azure workloads and internal apps inside your repos, on US hours.
By the Ryz Labs team · Updated October 2026
Hiring C# developers through Ryz gets you senior engineers who write modern, async C# and understand the .NET runtime underneath it. They are in the top 1% of the engineers we interview, they join your team and your codebase directly, and they work within an hour of US time zones.
What our C# developers work on
C# shows up in web services, line-of-business apps, desktop tools and cloud functions, so we match on the kind of C# you write. Around the language, our engineers work with ASP.NET Core, Entity Framework Core, SQL Server or Postgres, Azure, MassTransit or NServiceBus, and Docker. Common work:
- ASP.NET Core Web APIs and minimal APIs with authentication through Microsoft Entra ID or IdentityServer.
- Moving .NET Framework 4.x applications to .NET 8 and later, including WCF services and older Web Forms or MVC sites.
- Azure workloads: Functions, App Service, Service Bus, Cosmos DB and Azure SQL, provisioned with Bicep or Terraform.
- Internal business apps with Blazor, or desktop clients with WPF and WinUI that need ongoing support.
- Message-driven back ends with queues, sagas and retries for orders, billing and workflow systems.
- Services that call Azure OpenAI or other model APIs through Semantic Kernel or direct SDKs.
Skills we vet for
- Modern C#. Records, pattern matching, nullable reference types, primary constructors and LINQ used with care.
- Async and threading. async/await, ConfigureAwait, avoiding sync-over-async deadlocks, cancellation tokens and channels.
- ASP.NET Core. The middleware pipeline, dependency injection lifetimes, model binding, filters and output caching.
- Entity Framework Core. Change tracking, query translation, split queries, compiled queries and migration strategy.
- Memory and performance. The garbage collector generations, Span<T> and pooling for hot paths, and BenchmarkDotNet for measurement.
- Testing. xUnit or NUnit, WebApplicationFactory for integration tests, and Testcontainers for real databases.
- Azure and DevOps. Managed identities, Key Vault, GitHub Actions or Azure DevOps pipelines and Application Insights.
- Architecture. Clean or vertical-slice layouts, MediatR used deliberately, and modular monoliths versus microservices.
How we vet C# developers
Recruiters source C# engineers who have built and maintained production .NET systems, and they check what each person actually owned. Our in-house ARC system ranks the pipeline. Candidates complete a structured NTRVSTA AI interview on the language, the runtime and service design. Recruiters review them before and after the interview and put together a curated shortlist. AI scores are one input. People decide who moves forward.
Sample interview topics
- An ASP.NET Core API hangs under load and thread pool usage spikes. What sync-over-async patterns would you look for, and how do you prove the cause?
- A LINQ query against EF Core loads an entire table into memory before filtering. How does that happen, and how do you catch it in review?
- A scoped service is injected into a singleton. What goes wrong at runtime, and how does the container help you detect it?
- Plan the move of a .NET Framework 4.8 app with WCF endpoints and System.Web dependencies to .NET 8. What do you migrate first?
- Where would you use Span<T> or ArrayPool in a high-volume parser, and how would you measure whether it helped?
Ways to hire C# developers
| Option | Best for | Trade-offs |
|---|
| Freelance marketplace | Utilities and short bug fixes | Experience ranges from Unity scripting to enterprise APIs. Vetting and continuity fall on you. |
| Staffing or recruiting agency | Many .NET seats at once | Old .NET Framework and modern .NET experience can look the same on a resume. |
| In-house recruiting | Long-term owners of core systems | Long cycles and competition for senior engineers with cloud-era .NET skills. |
| Ryz Labs staff augmentation | Adding senior C# engineers to your current team | You lead the roadmap and code standards. Best when the work is already defined. |
| Ryz Labs AI pod team | An AI system built in Azure alongside your .NET services | A dedicated pod with a tech lead, backend and ML engineers. Scoped as a team with a plan first. |
Ryz is not the right fit if you want self-serve hourly freelance work, or if you need developers covering European or Asian hours. If you need engineers as direct employees with benefits, an employer-of-record partner is the right choice.
Why hire C# developers from Latin America
Microsoft technology has deep roots in Latin American enterprise software, and many senior C# engineers there have worked through the full arc from .NET Framework to cross-platform .NET. That history is useful when your codebase still contains both.
Our C# developers work within an hour of US time zones, so they can pair with your architects on a migration plan in the morning and have a pull request ready by the afternoon. They write and speak English at work and fit into your sprint process and tools.
Related roles
FAQ
Do your C# developers support older .NET Framework apps?
Yes. Many have maintained .NET Framework systems and led upgrades to current .NET. We can also place someone to keep a legacy app stable while a migration runs.
Do they work with Azure only, or AWS too?
Both. Azure is most common for C# shops, but our engineers also deploy .NET on AWS with Lambda, ECS and RDS.
How much does it cost to hire C# developers?
Custom quote, scoped per team. You receive a plan, a price and the names of the people who would do the work before you sign.
Who do we contract with, and what hours do they work?
You sign one contract with Ryz. Our engineers work with us as independent contractors, and we handle paying them. Their working day sits within an hour of US time zones.
Questions we didn't answer? Email info@ryzlabs.com.