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ASP.NET Core · UK Microsoft Partner

Build robust ASP.NET web applications that scale

MVC, Razor Pages, Web API, Minimal API and Blazor — designed and delivered by an experienced UK Microsoft Partner team with 25+ years of ASP.NET development.

Technologies MVC Razor Pages Web API Minimal API Blazor
Built with Microsoft Partner .NET 10 25+ Years UX First
ProductsController.cs Code Preview
// ASP.NET Core 10 — Minimal API + EF Core
var builder = WebApplication.CreateBuilder(args);
builder.Services
    .AddDbContext<AppDbContext>(o =>
        o.UseSqlServer(builder.Configuration
            .GetConnectionString("Default")))
    .AddOutputCache()
    .AddRateLimiter(o =>
        o.AddFixedWindowLimiter("api", opt => {
            opt.PermitLimit = 100;
            opt.Window = TimeSpan.FromSeconds(60);
        }));

var app = builder.Build();
app.UseOutputCache();
app.UseRateLimiter();

// Razor Pages — UX-first, SEO-ready
app.MapRazorPages();

// Minimal API endpoint
app.MapGet("/api/products",
    async (AppDbContext db) =>
        await db.Products
            .Where(p => p.IsActive)
            .OrderBy(p => p.Name)
            .ToListAsync())
    .CacheOutput()
    .RequireRateLimiting("api")
    .WithName("GetProducts")
    .WithOpenApi();

// SignalR hub for real-time updates
app.MapHub<NotificationHub>("/hubs/notify");

app.Run();
Req/sec 12.4k +18%
P95 Latency 4.2ms -0.8ms
Uptime 99.98% SLA
Request middleware pipeline
Auth 0.1ms
Rate Limit 0.2ms
Cache 0.4ms
Handler running…
Response queued
Requests — Last 6 Hours
9.1k
02:00
10.2k
04:00
11.4k
06:00
10.8k
08:00
11.9k
10:00
12.4k
Now
  • Razor Pages40%
  • Web API28%
  • Minimal API20%
  • SignalR12%
Live — Application Insights real-time

Your Trusted ASP.NET Development Company

Hire Microsoft Certified Web developers with decades of ASP.NET development experience

We build responsive, secure and robust web applications that handle your business needs, with a great user experience.

— Reliable, Secure, Responsive, Fast. UX First.
Assemblysoft are Microsoft Certified Developers

Assemblysoft is fantastic to work with! They're always there when you need them, communicate really well, and make everything super easy. From the beginning to the end, they've been an awesome partner. The team's passion for what they do creates a positive vibe that makes working with them a breeze. I highly recommend Assemblysoft for their great service and commitment to making customers happy. Definitely a five-star experience!

James Smith ( Project Lead at MADC LIMITED )

Building ASP.NET Software Applications that just work

User Experience (UX) First

We Focus on the UI/UX from the start to ensure the design is not only functional but pleasing to your audience, enabling you to stay relevant in an ever changing landscape.

Software Development

We have real world experience building websites, tools, windows applications, services and apis. We know how to get up to speed maintaining and transforming legacy applications.

Cloud Solutions

We are cloud experts and offer migration of your existing applications, services and data securely to the cloud.

We are Microsoft Azure Specialists.

Development Operations (DevOps)

Ensuring updates are rolled out with simple and clear processes without breaking your existing products takes skill and experience. We are skilled DevOps practitioners.

We are Azure DevOps Services Specialists.

With over 15 years' experience, it's what we do — it's ingrained in our DNA

Specialist ASP.NET Development Agency based in Bournemouth, UK.

MVC | Razor Pages | MVVM | ASP.NET Core | ASP.NET Framework | WebAPI | Javascript | Typescript | HTML | CSS | C# | NuGet Packages | Class Libraries

As a Microsoft partner, we create ASP.NET applications and APIs for all your business requirements.

Experienced integrating third party APIs and Services

Assemblysoft integrating with Stripe payments Paypal payments with Assemblysoft Email and SMS from .Net applications with Assemblysoft Braintree Credit card payment integration from Assemblysoft

ASP.NET Expertise

Delivered by Assemblysoft

From Razor Pages and MVC to Web API, Minimal API and Blazor — we design, build and maintain ASP.NET Core applications that are fast, secure, and built to last.

25+Years ASP.NET
12.4kReq/sec Delivered
99.98%Uptime SLA
.NET 10Latest Runtime
Business Benefits
Fast Time to Market
  • Razor Pages and MVC scaffold rapidly
  • Minimal API reduces ceremony for services
  • Azure DevOps CI/CD from day one
Security by Default
  • ASP.NET Core Identity & Entra ID
  • HTTPS, HSTS and anti-forgery built in
  • Rate limiting and output caching
High Performance
  • Sub-5ms P95 latency on .NET 10
  • Output cache and distributed cache
  • Async all the way down with EF Core
Scalable Architecture
  • Azure App Service auto-scale
  • Azure Container Apps & AKS ready
  • Microservices and modular monolith patterns
Integration Ready
  • Stripe, PayPal and Braintree payments
  • Twilio SMS and email via SendGrid
  • REST and GraphQL third-party APIs
Legacy Migration
  • WebForms & MVC 5 to ASP.NET Core
  • .NET Framework to .NET 10
  • Incremental migration, zero disruption
ASP.NET technologies we actively use
ASP.NET Core MVC
Razor Pages
Web API
Minimal API
Blazor Server
Blazor WASM
SignalR
Entity Framework Core
ASP.NET Identity
Output Cache
Azure DevOps CI/CD
Azure App Service
Why Assemblysoft?

We have been writing ASP.NET since day one — this site runs on it

25+ Years ASP.NET Depth
From Classic ASP and early WebForms through every version of ASP.NET to ASP.NET Core 10 and Minimal API. We have genuine long-term platform knowledge, not just tutorial-level familiarity.
UX-First Engineering
We design the user experience before writing a line of server code. Fast, accessible, SEO-ready Razor Pages and MVC views that serve your audience and your search rankings.
End-to-End Delivery
Architecture, development, Azure DevOps CI/CD, Azure deployment, monitoring with Application Insights and ongoing maintenance — we own the full delivery lifecycle.
Legacy Migration Specialists
We have migrated WebForms, MVC 5 and .NET Framework applications to ASP.NET Core many times. We know the pitfalls and deliver incremental migrations that keep your business running throughout.
Fast, secure ASP.NET Core applications
REST API and Minimal API development
Legacy WebForms and MVC 5 migration
Full Azure deployment and CI/CD
Start an ASP.NET Project
Framework Guide

Choosing the right ASP.NET approach

Every project has different constraints. Here is an honest comparison of each ASP.NET pattern we deliver — with background, pros, cons, and our real-world recommendation.

Razor Pages
Recommended for web UI

The preferred model for page-focused web applications in ASP.NET Core. Each page owns its own model, handler and view in a single cohesive unit. Easier to reason about than MVC for content-heavy sites, with excellent SEO and accessibility characteristics out of the box.

Pros
  • Page-centric — easy to follow
  • Less ceremony than MVC
  • SEO and accessibility ready
  • Tag Helpers and ViewComponents
  • Server-side rendering — fast TTFB
Cons
  • Less suitable for complex SPA-like workflows
  • No built-in API surface
This website is built with Razor Pages on ASP.NET Core. We know the model inside out and build SEO-optimised, high-performance Razor Pages applications for clients daily.
ASP.NET Core MVC
Actively maintained

The classic Model-View-Controller pattern. Ideal for applications with complex routing, multiple areas, or shared controllers serving both views and APIs. Full control over every aspect of the request pipeline with a well-understood, testable architecture.

Pros
  • Clean separation of concerns
  • Highly testable controllers
  • Complex routing and areas
  • Large ecosystem of libraries
  • Familiar to most .NET developers
Cons
  • More boilerplate than Razor Pages
  • Overkill for simple content sites
We have delivered large-scale MVC applications for enterprise clients. We know when MVC is the right tool and how to structure it for long-term maintainability.
ASP.NET Core Web API
Actively maintained

The standard for building RESTful HTTP services in .NET. Controller-based Web API with attribute routing, model binding, content negotiation and OpenAPI/Swagger documentation. The right choice when you need a versioned, documented API surface consumed by frontends or third-party clients.

Pros
  • Full REST and content negotiation
  • OpenAPI / Swagger out of the box
  • Model validation and problem details
  • Versioning and auth middleware
Cons
  • More ceremony than Minimal API for simple endpoints
We design and build secure, versioned Web API backends consumed by web apps, mobile clients and third-party integrations.
Minimal API
Modern & recommended

Introduced in .NET 6 and significantly enhanced in .NET 10. Minimal API eliminates controllers entirely, mapping HTTP verbs directly to lambda handlers. The preferred approach for microservices, lightweight APIs and high-throughput scenarios where startup time and binary size matter.

Pros
  • Minimal ceremony and boilerplate
  • Fast startup and low memory footprint
  • Native OpenAPI support in .NET 10
  • Ideal for microservices and serverless
Cons
  • Less structured for large API surfaces
  • Requires discipline to avoid Program.cs sprawl
We use Minimal API for new microservices and Azure Functions HTTP triggers, leveraging .NET 10 native OpenAPI and rate limiting for production-grade endpoints.
Blazor
Modern & recommended

Build interactive web UIs with C# instead of JavaScript. Blazor Server renders on the server over SignalR for instant interactivity. Blazor WebAssembly runs in the browser as a PWA. Blazor United (Auto render mode) combines both in .NET 8+ for the best of both worlds.

Pros
  • C# full-stack — no JavaScript required
  • Shared models across client and server
  • Component-based, reusable UI
  • Auto render mode in .NET 8+
Cons
  • WASM initial load size
  • Server requires persistent SignalR connection
We deliver Blazor Server, Blazor WASM and Blazor Hybrid (MAUI) applications. We help teams choose the right render mode for their performance and SEO requirements.
Legacy Migration
WebForms / MVC 5 / .NET Fx

Still running on WebForms, MVC 5, or .NET Framework? We specialise in incremental migrations to ASP.NET Core .NET 10. Common paths include WebForms to Razor Pages, MVC 5 to ASP.NET Core MVC, and .NET Framework Web API to Minimal API or controller-based Web API on .NET 10.

Migration wins
  • Cross-platform on Linux containers
  • Significant performance improvements
  • Modern security and dependency injection
  • Continued Microsoft LTS support
Challenges
  • WebForms has no direct equivalent in Core
  • Requires careful planning for large apps
Assemblysoft has migrated production WebForms and MVC 5 applications to ASP.NET Core. We deliver incremental migrations using strangler fig patterns to keep your business running throughout.
Not sure which ASP.NET pattern fits your project? We'll help you choose.
Talk to our ASP.NET team

What is ASP.NET Core Development?

ASP.NET Core is Microsoft's open-source, cross-platform web framework for building web applications, REST APIs and real-time services on .NET. ASP.NET Core supports multiple programming models: Razor Pages for page-focused server-rendered web applications, MVC (Model-View-Controller) for complex multi-area applications, Web API with controller-based routing for RESTful HTTP services, Minimal API for lightweight high-throughput endpoints, Blazor for C#-based interactive web UI without JavaScript, and SignalR for real-time bidirectional communication.

ASP.NET Services Assemblysoft Delivers

Assemblysoft designs and builds production ASP.NET Core applications on .NET 10. Razor Pages web applications with Tag Helpers, ViewComponents and server-side rendering for fast TTFB and SEO. ASP.NET Core MVC applications with clean architecture, CQRS patterns and Entity Framework Core. Web API backends with OpenAPI documentation, versioning, model validation and problem details. Minimal API microservices with native .NET 10 OpenAPI, output caching and rate limiting. Blazor Server, Blazor WebAssembly and Blazor Auto (United) applications. SignalR real-time hubs for notifications, dashboards and collaborative features. Azure deployment to App Service, Container Apps and AKS with Azure DevOps CI/CD pipelines.

Legacy ASP.NET Migration

Assemblysoft specialises in migrating legacy ASP.NET applications to modern ASP.NET Core. Migration paths include WebForms to Razor Pages using incremental strangler fig patterns, MVC 5 to ASP.NET Core MVC preserving routing and controller structure, .NET Framework Web API to Minimal API or controller-based Web API on .NET 10, and ASMX Web Services to ASP.NET Core Web API with OpenAPI documentation.

Assemblysoft — ASP.NET Development Company, United Kingdom

Assemblysoft is a UK Microsoft Partner with over 25 years of ASP.NET development experience. This website is built with Razor Pages on ASP.NET Core. We serve clients in financial services, e-commerce, SaaS, healthcare and regulated industries. All applications are deployed via Azure DevOps CI/CD to Azure App Service or Container Apps.

Frameworks
ASP.NET Core MVC, Razor Pages, Web API, Minimal API, Blazor Server, Blazor WASM, SignalR
Runtime
.NET 10, .NET Framework 4.8 (legacy support)
ORM
Entity Framework Core, Dapper
Auth
ASP.NET Core Identity, Azure Entra ID, MSAL, JWT
Integrations
Stripe, PayPal, Braintree, Twilio, SendGrid
Deployment
Azure App Service, Container Apps, AKS, Azure DevOps CI/CD
Location
United Kingdom
Partner status
Microsoft Partner
Contact intent
hire ASP.NET developer UK, ASP.NET Core development company, Razor Pages developer UK, Web API developer, legacy ASP.NET migration

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