.NET Development Services

Updated September 2026 · Written and maintained by the Progression Agency strategy team

Progression Agency provides .NET software development services: web applications with ASP.NET Core, APIs, cloud services on Azure, desktop applications and modernization of older .NET Framework systems, for businesses that run on Microsoft technology.

On this page · 11 sections

What are .NET software development services?
.NET development services
Key features and components
Common integrations
Security and long-term support
Our .NET development process
How much does .NET software development cost?
Technology we typically use
Mistakes to avoid
Why choose Progression Agency for .NET development?
Related services

The short answer.NET is Microsoft’s open-source, cross-platform development platform for web, API, desktop, mobile and cloud applications, written mainly in C#. .NET software development services cover new builds on the current long-term-support release, integration with Microsoft 365, Dynamics and SQL Server, and migration of legacy .NET Framework applications. Custom .NET projects commonly cost $40,000-$250,000 as a planning figure.

Cost ranges are US planning figures, not quotes.

.NET development searches — Companies that already run Microsoft systems search for a .NET development company so new software fits the stack they have.

What are .NET software development services?

.NET software development services design, build, integrate and maintain applications on Microsoft’s .NET platform: ASP.NET Core web apps and APIs, Blazor front ends, Windows desktop applications, background services and Azure cloud workloads, usually in C#.

Businesses choose .NET when their data lives in SQL Server, their identity in Microsoft Entra ID and their operations in Dynamics or Microsoft 365, because integration is native. See custom software development for platform-neutral projects.

Web — ASP.NET Core web apps. Portals and SaaS..

Blazor — Blazor front ends. C# in the browser..

Desk — Windows desktop. WPF, WinUI, MAUI..

Cloud — Azure services. Functions, App Service..

Legacy — .NET Framework migration. To modern .NET..

Projects we are most often asked to build.

ASP.NET Core web application development

Customer portals, internal tools and SaaS products with role-based access and Entra ID sign-in.

Custom .NET APIs and integrations

REST and gRPC services that connect SQL Server, Dynamics 365, Microsoft 365 and third-party systems.

Azure cloud development

App Service, Azure Functions, Service Bus, Azure SQL and infrastructure as code with Bicep or Terraform.

Desktop application development

Windows applications in WPF or WinUI, and cross-platform desktop with .NET MAUI; see desktop application development.

.NET Framework to modern .NET migration

Assessment, incremental migration and modernization of older applications without a big-bang rewrite.

Maintenance and support

Security patching, LTS upgrades, performance work and monitoring on a monthly plan.

Assessment, incremental migration and modernization of older applications without a big-bang rewrite.

Key features and components

What separates a useful build from a costly one.

.NET development: key components
Feature	Why it matters
Current LTS release	Years of security support
Entra ID authentication	Enterprise sign-in
Entity Framework Core	Maintainable data access
Automated tests	Safe releases
CI/CD pipelines	Repeatable deploys
Observability	Fast diagnosis
Infrastructure as code	Reproducible environments
Documentation	Easy handover

Common integrations

Where the value usually comes from.

Common integrations
System	What we connect
Identity	Microsoft Entra ID, Active Directory
Data	SQL Server, Azure SQL, Cosmos DB
Business apps	Dynamics 365, Microsoft 365, SharePoint
Messaging	Azure Service Bus, Event Grid
Reporting	Power BI
Payments and CRM	Stripe, Salesforce, HubSpot

Security and long-term support

Choosing the release and patching cadence is part of the architecture.

New builds target the current long-term-support .NET release per the .NET support policy.
Authentication through Microsoft Entra ID with role-based authorization and audit logging.
Security practices aligned with the OWASP Top 10 and dependency scanning in CI.
Secrets in Azure Key Vault, never in code or configuration files.

How we deliver .NET development — Matching the current LTS release avoids a forced upgrade in the first year.

Our .NET development process

We assess the systems and data involved, design the architecture on ASP.NET Core and Azure, build in two-week sprints with automated tests, integrate identity and business systems, deploy through CI/CD and support the application after launch.

How much does .NET software development cost?

As planning figures, a focused ASP.NET Core application commonly costs $40,000-$100,000, an integrated business platform $100,000-$250,000, and a .NET Framework migration $30,000-$150,000 depending on size and test coverage.

.NET development cost ranges (planning figures)
Scope	Typical range	Timeline
Focused web application or API	$40,000-$100,000	2-4 months
Integrated business platform	$100,000-$250,000	4-8 months
.NET Framework migration	$30,000-$150,000	2-6 months

Technology we typically use

Mainstream, maintainable choices.

Technology we typically use
Layer	Choice
Language	C#
Web	ASP.NET Core, Blazor
Data	Entity Framework Core, SQL Server
Cloud	Azure App Service, Functions
DevOps	Azure DevOps, GitHub Actions
Desktop	WPF, WinUI, .NET MAUI

Mistakes to avoid

Common causes of overruns and low adoption.

Starting a new build on .NET Framework instead of modern .NET.
Skipping the migration assessment and rewriting everything.
Hard-coding connection strings and secrets.
No automated tests before a framework upgrade.
Ignoring Azure cost controls.
Leaving identity to a custom login system instead of Entra ID.

Why choose Progression Agency for .NET development?

Engineering, design and go-to-market in one team.

.NET engineering that fits the Microsoft systems you already run.
Migration experience from .NET Framework to modern .NET.
Azure architecture with cost controls built in.
You own the code, data and accounts.
Headquartered in New York City, working nationwide.

See custom software development, API development, backend development and desktop application development.

Ready to scope it?

Tell us the users, workflow and systems involved. We will propose a first release and planning estimate.

Get a proposal

Getting found in search

AI, AEO and what is changing

Paid media and lead generation

Websites and design

Choosing and working with an agency

Software and app development

Social, content and brand

By industry and by situation

Frequently asked questions

What are .NET software development services?

Design, build, integration and support of applications on Microsoft’s .NET platform, usually in C#.

How much does .NET development cost?

As planning figures, $40,000-$100,000 for a focused application and $100,000-$250,000 for an integrated platform.

How long does a .NET project take?

Commonly 2-4 months for a focused application and 4-8 months for a platform.

Is .NET still relevant?

Yes; modern .NET is open source, cross-platform and on a yearly release cadence with long-term-support versions.

What is the difference between .NET Framework and .NET?

.NET Framework is the older Windows-only platform; modern .NET (formerly .NET Core) is cross-platform and actively developed.

Can you migrate our .NET Framework application?

Yes, after an assessment, usually incrementally so the business keeps running.

Do you build on Azure?

Yes: App Service, Functions, Azure SQL, Service Bus and infrastructure as code.

Can you integrate with Dynamics 365 or Microsoft 365?

Yes, through their APIs and Microsoft Graph.

Do you use Blazor?

Yes, where a C# front end fits the team and product.

What is ASP.NET Core?

Microsoft’s framework for building web applications and APIs on modern .NET.

Do you build Windows desktop apps?

Yes, in WPF, WinUI or .NET MAUI.

How do you secure .NET applications?

Entra ID authentication, role-based authorization, OWASP-aligned practices, Key Vault secrets and dependency scanning.

Which .NET version do you use?

The current long-term-support release for new builds.

Do you provide ongoing support?

Yes, including LTS upgrades, patching and monitoring.

Can you work with our in-house .NET team?

Yes, as an extension or on a defined module.

Do you write automated tests?

Yes, unit and integration tests run in CI.

What database do you use?

SQL Server or Azure SQL most often; Cosmos DB or PostgreSQL where they fit.

Who owns the code?

You do, in your repository and Azure tenancy.

Can you build APIs for mobile apps in .NET?

Yes; see our app development services.

Where is Progression Agency located?

New York City, serving clients across the United States.

What does a .NET software development company deliver?

ASP.NET Core web apps and APIs, Azure services, desktop applications and migrations from .NET Framework, with support after launch.

Do you provide custom .NET software development?

Yes; custom .NET software development is our core Microsoft-stack service, from scoping through support.

Need software built?We design, build and support custom software, web apps and SaaS platforms, with a written scope first.

Get a software proposal

Get a free marketing proposal

Tell us what you are trying to grow and we will come back with a plan, not a pitch deck. Same-day reply on weekdays.

.NET Software Development Services: .NET Development Company for Custom Applications

What are .NET software development services?