.NET Development
Build and modernise .NET applications, faster
We build and modernise .NET applications for UK organisations, from ASP.NET Core APIs to full enterprise platforms. As a Microsoft Solutions Partner, we deliver in C# and .NET with AI-augmented engineering that is faster without cutting quality.
What .NET development with Talk Think Do means
.NET development is the building and modernising of software on Microsoft's .NET platform, written in C#. It is the right choice for organisations that want secure, maintainable applications that integrate cleanly with the Microsoft and Azure stack. This page is for technical and procurement buyers looking for a framework-specific .NET partner, not a generalist agency.
We cover the full range: new ASP.NET Core APIs and web apps, enterprise .NET platforms, and the modernisation of legacy .NET Framework systems. Every engagement is delivered by a senior UK team, on Azure, with full source code ownership.
The .NET problems we are brought in to solve
Most organisations do not come to us for .NET in the abstract. They come because one of these is holding them back.
Stuck on unsupported frameworks
WCF, Web Forms, and older .NET Framework versions are out of mainstream support or heading there. Every month on an unsupported stack is a growing security, compliance, and recruitment risk, and the gap to modern .NET only widens.
Rising cost, shrinking talent
Engineers who know your legacy .NET are harder and more expensive to find. Knowledge leaves with the people who hold it, and each change becomes slower, riskier, and more dependent on a shrinking pool of specialists.
Delivery that cannot keep up
Releases take too long, environments are fragile, and the backlog grows faster than the team can clear it. The business waits on IT while competitors ship, and confidence in delivery erodes.
Integration and technical debt
Tightly coupled services and brittle integrations make every change expensive. Adding one feature means touching code no one wants to touch, so even small improvements stall.
.NET development capabilities
From new ASP.NET Core APIs to the modernisation of legacy .NET Framework systems, all on Azure and all delivered by a senior team.
ASP.NET Core APIs and services
.NET web applications
Enterprise .NET platforms
.NET Framework to modern .NET
Retiring legacy stacks
Azure-native .NET
AI-augmented .NET engineering
Every engineer uses AI-augmented development as part of our standard process. That makes delivery 40 to 50% faster than a traditional team, with 84% of our code now AI-authored and human-reviewed. The figures are measured on live projects and published openly, not estimated.
Architecture, security, and quality decisions stay with experienced people. AI accelerates the work; it does not make the calls. Read the detail in our AI Velocity Report.
From legacy estate to supported .NET
A six-stage lifecycle with a security and licence gate, whether we are building new or modernising existing .NET.
Our .NET delivery process
The same structured, transparent process on every project, accelerated by AI where it adds genuine value.
Discovery and assessment
We map your goals, existing systems, and .NET framework versions, and assess the estate for risk, dependencies, and unsupported components. You receive a prioritised plan with effort and value estimates, and an honest view of where modernisation pays off and where it does not.
Architecture and target framework
We agree the right .NET target (ASP.NET Core on current .NET), service boundaries, and integration points. Cloud-native Azure architecture and infrastructure-as-code templates are defined up front, so the build has solid foundations rather than assumptions.
Build in C# and .NET
We deliver in agile sprints using AI-augmented engineering. Code is version-controlled, reviewed, and tested throughout, with regular demos so you interact with working software, not status reports. Architecture and quality decisions stay with senior engineers.
Test, security, and licence scanning
Every build goes through automated testing, a security review, and open-source licence scanning. AI-assisted code is held to exactly the same standard as any other code in our process, with nothing reaching production unreviewed.
Launch and ongoing support
We deploy to Azure with zero-downtime releases and 30 days of free post-launch care. Optional managed support keeps your .NET applications patched, monitored, and evolving long after go-live.
.NET in production, at national scale
We support and enhance the .NET integration platform behind CalMac Ferries, the UK's largest ferry network. It underpins around 160,000 sailings and 5 million passenger journeys a year, with a focus on reliable day-to-day operation and swift incident resolution. For the Department for Education, we helped move the Calculate Funding Service, which allocates around £60 billion a year to schools, off a struggling on-premise system onto a scalable Azure architecture.
Sailings a year
Passengers a year
DfE funding allocated
Read the CalMac case study or the Department for Education case study.
"Talk Think Do have been a valuable support to CalMac, taking the time to understand our needs and provide a seamless support service whilst being responsive and reactive to additional requests and challenges."
Procurement Manager
CalMac Ferries
A framework-specific .NET team, not a generalist agency. Microsoft Solutions Partner engineers who build, modernise, and support C# and .NET in production, with full source code ownership on every engagement.
About Talk Think Do
Talk Think Do is a UK-based software development company founded by Matt Hammond and headquartered in Bournemouth, Dorset. We are a Microsoft Solutions Partner with designations in Azure Infrastructure, Digital and App Innovation, and DevOps and GitHub.
C# and .NET on Azure is core to what we build. We design new ASP.NET Core systems and modernise legacy .NET estates, and we hold ISO 27001 certification, Cyber Essentials Plus accreditation, and approved Crown Commercial Service supplier status on the G-Cloud and Digital Outcomes frameworks.
Our clients include:
- Department for Education
- CalMac Ferries
- Livestock Information Services
- Hachette Learning
- Third Space
AI-augmented development is central to how we work. Every engineer uses AI tools such as Cursor, Claude Code, and GitHub Copilot daily, and we run a quarterly evaluation cycle to keep improving. The result is .NET software delivered faster, without compromising architecture, security, or code quality.
Seen enough? Let's talk through your requirements.
Book a free consultation.NET development: frequently asked questions
What is .NET development?
.NET development is the building of applications on Microsoft's .NET platform, primarily in the C# language. It covers web APIs and applications in ASP.NET Core, background and desktop services, and cloud-native systems on Azure. As a Microsoft Solutions Partner, Talk Think Do builds new .NET applications and modernises existing ones for UK organisations.
Do you build in ASP.NET Core?
Yes. ASP.NET Core is our default for new web APIs and applications. It is cross-platform, high-performance, and fully supported on current .NET. We use it for everything from public-facing portals to internal line-of-business systems and high-throughput back-end services on Azure.
Can you modernise our legacy .NET Framework application?
Yes. We migrate .NET Framework applications to modern .NET, retire unsupported components such as WCF and Web Forms, and re-platform onto Azure where it makes sense. We assess each system first and recommend the lowest-risk path, whether that is an incremental migration or a targeted rebuild. See our guide to modernising legacy .NET applications with AI.
What versions of .NET do you work with?
We build new work on the current long-term support release of .NET and keep projects current as new versions ship. We also work across older .NET Framework versions when assessing and modernising existing systems, so we can meet you wherever your estate is today and move it forward safely.
Can we hire a dedicated .NET team rather than individual developers?
Yes. Most clients engage a small, senior .NET team rather than hiring individual contractors. You get a solutions architect, full-stack .NET engineers, and a delivery manager working together, with full source code ownership and no offshore handover gaps. The people you meet at the start are the people who do the work.
Who owns the .NET code you write, and is AI-assisted code safe to use?
You own all source code we deliver. Our engineers direct, review, and modify any AI-assisted output, and every build is security reviewed and scanned for open-source licence issues before it ships. Our ISO 27001 certification and Cyber Essentials Plus accreditation apply to all delivery, including AI-augmented work.
How much does .NET development cost and how fast can you deliver?
A focused application typically starts around £50,000, while a complex enterprise .NET platform can run to £500,000 or more. Cost depends on scope, integrations, and compliance needs. AI-augmented delivery means more gets built within the same budget. We provide a detailed estimate after a free discovery session.
Go deeper on .NET
Modernising Legacy .NET Applications with AI
The enterprise playbook for bringing ageing .NET systems up to current standards on Azure.
.NET Framework to .NET 10 Migration
A step-by-step, AI-assisted approach to migrating off .NET Framework safely.
Claude Code for .NET Developers
Getting started with Claude Code for C# and .NET: setup, IDE integration, and practical workflows.
What is AI-Augmented Development?
The meaning, practice, and production evidence behind our delivery model.
Signs Your Legacy System Is Costing You
Eight warning signs of hidden legacy costs across maintenance, talent, and security.
Harness Engineering for Coding Agents
How we steer AI coding agents safely on .NET and SQL Server stacks.
See how AI is changing how we build software
Our quarterly AI Velocity Report tracks real delivery metrics from live projects: how much of our code is AI-authored, how delivery timelines compare to baseline, and which tools are making a measurable difference. No marketing spin, just honest data from a team that builds software every day.
Read the latest AI Velocity ReportExplore our other services
Custom Software Development
Our parent service: bespoke software on Azure with full code ownership and AI-augmented delivery.
Enterprise Software Development
Mission-critical .NET systems at scale, with ISO 27001 security and G-Cloud approval.
Legacy Application Modernisation
Transform outdated .NET systems into modern, scalable Azure platforms using the 6 Rs framework.
Legacy Application Support
SLA-backed managed support for legacy .NET and SQL Server systems, without a rebuild.
API and Integration Services
REST, gRPC, and GraphQL APIs in .NET that connect your systems cleanly.
Claude Code Development
AI-accelerated .NET delivery using Claude Code, with full IP ownership.
Ready to build or modernise in .NET?
Tell us about your .NET project or your legacy estate. We will give you honest advice, a clear plan, and a cost estimate, with no obligation.
Book a free consultationor call 01202 375647