High-Performance Enterprise Applications with C# and ASP.NET Core

We specialize in C# backend development, ASP.NET Core development, and server-side .NET technologies. Our API development in C# follows best practices including CQRS pattern and Dapper ORM. We deploy .NET applications as turnkey backend solutions. Our expertise includes C# backend development, ASP.NET Core development, server-side .NET, API development in C#, Entity Framework Core, Dapper ORM, CQRS pattern, Minimal API, JWT authentication, SignalR real-time, deploy .NET applications, and turnkey backend solutions. When your REST API on Node.js or Python starts slowing down at just a few thousand requests per second, and synchronous calls to PostgreSQL turn latency into a crap shoot—it’s time to switch to a platform with predictable performance. According to Microsoft documentation, ASP.NET Core on Kestrel handles 50–80K RPS on a single core, which is 3–5 times faster than typical Node.js setups. We have rewritten dozens of backends from Node.js and Python to C#—performance increased 3–5 times while preserving the architecture. For example, one client’s e-commerce API went from 10K to 55K RPS after migration, reducing server costs by 60%.

C# is chosen not only for speed. Strong typing, built-in DI, OpenAPI out of the box, and a rich NuGet ecosystem reduce total cost of ownership by up to 40%. If your project already has a WPF client or Blazor interface, a monorepo on a single language eliminates duplication of business logic. We have been working with .NET for over 10 years and have completed more than 50 projects: from highload APIs to corporate portals with Active Directory.

The development result includes:

• REST/GraphQL API with automatic OpenAPI specification
• Authentication via JWT, Azure AD, or IdentityServer
• Background jobs (Hangfire, IHostedService)
• Real-time notifications (SignalR)
• CI/CD with Docker and orchestration
• Full documentation and team training

When Is .NET Indispensable?

Enterprise projects with thousands of RPS, integration with Active Directory/Azure AD, and requirements for transactional consistency are the domain of .NET. If your team already knows C#, the choice is obvious. Even for small projects, ASP.NET Core Minimal API allows you to start without excessive boilerplate.

Designing Backends in C#: Our Methodology

Below are real code snippets that have passed code review and run in production.

Minimal API and JWT Authentication

var builder = WebApplication.CreateBuilder(args); builder.Services.AddDbContext<AppDbContext>(opt => opt.UseNpgsql(builder.Configuration.GetConnectionString("Default"))); builder.Services.AddScoped<IUserService, UserService>(); builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme) .AddJwtBearer(opt => { opt.TokenValidationParameters = new TokenValidationParameters { ValidateIssuer = true, ValidIssuer = builder.Configuration["Jwt:Issuer"], ValidateAudience = false, IssuerSigningKey = new SymmetricSecurityKey( Encoding.UTF8.GetBytes(builder.Configuration["Jwt:Secret"]!)) }; }); var app = builder.Build(); app.MapGet("/users/{id:int}", async (int id, IUserService svc) => await svc.GetByIdAsync(id) is { } user ? Results.Ok(user) : Results.NotFound()); app.MapPost("/users", async (CreateUserDto dto, IUserService svc) => { var user = await svc.CreateAsync(dto); return Results.Created($"/users/{user.Id}", user); }); app.Run(); 

This code is the standard skeleton of a production service. For complex projects, we use Vertical Slice Architecture with MediatR, keeping each scenario isolated.

EF Core vs Dapper: Comparison Table

In our projects, we often combine both approaches: EF Core for standard queries, Dapper for heavy reporting. This yields up to 40% reduction in infrastructure costs.

Output Cache and Background Jobs

builder.Services.AddOutputCache(opt => { opt.AddPolicy("products", p => p.Expire(TimeSpan.FromMinutes(10)).Tag("products")); }); app.MapGet("/products", async (IProductRepo repo) => await repo.GetAllAsync()) .CacheOutput("products"); app.MapPost("/products", async (CreateProductDto dto, IOutputCacheStore cache, ...) => { var product = await svc.CreateAsync(dto); await cache.EvictByTagAsync("products", CancellationToken.None); return Results.Created($"/products/{product.Id}", product); }); 

Output Cache is a built-in solution starting from .NET 8. For background jobs, we use IHostedService or Hangfire depending on queue complexity.

Deployment and Health Checks

FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build WORKDIR /src COPY ["MyApi.csproj", "."] RUN dotnet restore COPY . . RUN dotnet publish -c Release -o /app/publish FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS runtime WORKDIR /app COPY --from=build /app/publish . ENV ASPNETCORE_URLS=http://+:8080 ENV ASPNETCORE_ENVIRONMENT=Production EXPOSE 8080 ENTRYPOINT ["dotnet", "MyApi.dll"] 

Health checks for orchestrators:

builder.Services.AddHealthChecks() .AddNpgsql(connStr, name: "postgres") .AddRedis(redisConn, name: "redis"); app.MapHealthChecks("/health/live", new HealthCheckOptions { Predicate = _ => false }); app.MapHealthChecks("/health/ready"); 

What Is the Cost of ASP.NET Core Development?

Typical project cost starts at $5,000 for a basic API and can go up to $50,000 for a complex enterprise system. Our optimization reduces cloud spend by $2,000–$5,000 monthly. For instance, one client saved $3,500 per month after migrating to our C# backend. We provide a detailed quote after requirements review.

Configuring JWT in ASP.NET Core

1. Install the package Microsoft.AspNetCore.Authentication.JwtBearer.
2. In Program.cs, add AddAuthentication with parameters: ValidIssuer, ValidAudience, IssuerSigningKey.
3. Set up authorization via AddAuthorization with policies.
4. Apply middleware: app.UseAuthentication(); and app.UseAuthorization();.

Configuration example is provided above. In production, we add Refresh Tokens and use IdentityServer for centralized management.

Typical Mistakes in ASP.NET Core Development

• N+1 queries in EF Core — use .Include() or projections via .Select().
• Lack of async/await in I/O operations — thread blocking sharply reduces throughput.
• Synchronous password hashing — bcrypt or PBKDF2 are mandatory.
• Ignoring middleware pipeline order — middleware registration order is critical.

Development Deliverables

We provide full API documentation (Swagger), access to source code, and training for your team.

Timeline Estimation

A simple REST API (10–15 endpoints, one DB, JWT): 5–8 business days. A full-featured service with roles, background jobs, SignalR, and CI/CD: 3–5 weeks. Migration from .NET Framework to .NET Core is evaluated separately after a code audit—typically takes 2–6 weeks. Typical project cost starts at $5,000 for a basic API and can go up to $50,000 for a complex enterprise system, but we provide a detailed quote after requirements review.

For a typical mid-size API, our optimization reduces cloud spend by $2,000–$5,000 monthly.

Discuss your project with our architect: write to us with a brief description of the task — we'll estimate the timeline and cost within 1–2 business days. We guarantee code quality and provide an official 3-month warranty.