The companies below provide .NET web development for US businesses, including new application builds, cloud migrations, system integrations, and modernization of older Microsoft-based software. The list covers US-based consultancies and international engineering firms with established operations or service delivery in the American market.
Gilzor develops custom web and mobile products for businesses that need more than a standard website. Its work includes business applications, backend systems, user-facing portals, and connected mobile solutions. The company can manage product discovery, UI/UX design, development, testing, and post-launch support within one project.
For .NET projects, Gilzor is relevant to companies looking for custom architecture rather than an off-the-shelf platform. Its published portfolio includes healthcare and other business applications built for international clients, including a web and mobile system created for a US medical laboratory.
Leobit has a dedicated .NET practice covering custom applications, ASP.NET development, cloud software, and legacy modernization. Its engineers work with .NET Core, ASP.NET Core, C#, Blazor, Entity Framework Core, and Microsoft Azure. This technical range suits web products that require a Microsoft-based backend and a modern browser interface.
The company supports complete product delivery as well as dedicated engineering teams. Its US headquarters is in Austin, while additional development centers operate in Europe. Published industry experience includes fintech, real estate, logistics, education, and legal technology.
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Vention assembles engineering teams for web development, platform modernization, and product expansion. Its technology capabilities include Microsoft .NET alongside JavaScript frameworks, cloud platforms, databases, DevOps tools, and mobile technologies.
The company is a practical option for organizations that already have an internal product or engineering function but need more development capacity. Engagements can involve backend development, API creation, cloud migration, quality assurance, or complete product delivery. Vention maintains a New York office and works with companies ranging from funded startups to established enterprises.
Saritasa builds custom applications for companies with operational requirements that standard software cannot easily address. Its .NET services cover application architecture, backend engineering, web APIs, database work, integrations, and support for existing systems.
Beyond .NET, the company provides frontend development, mobile applications, IoT solutions, virtual reality development, and UI/UX design. That broader capability can be useful when a web platform must communicate with mobile devices, hardware, or several internal systems. Saritasa has physical offices in California and Florida, along with distributed teams in several US states.
A-Listware provides web development and outsourced engineering teams for companies that need additional technical capacity. Microsoft .NET is part of its web technology stack, alongside Java, JavaScript, and other backend and frontend technologies.
Its services cover new application development, modernization, application management, cloud solutions, testing, and ongoing support. Clients can use A-Listware for a defined software project or add engineers to an existing delivery team. The company lists a US presence in North Bergen, New Jersey, and works with sectors including finance, healthcare, retail, logistics, and manufacturing.
Keyhole Software supplies senior US-based consultants for .NET application development and modernization. Its Microsoft practice works with C#, .NET Core, ASP.NET Core, Azure, APIs, microservices, and cloud-native architecture.
The company is particularly relevant to organizations dealing with mature business systems. Its teams can assess an existing codebase, redesign application architecture, move software to newer .NET versions, or build a replacement platform in stages. Keyhole states that its employees reside in the United States and that client development work is not subcontracted outside the country.
Itexus develops financial software for banks, fintech companies, lenders, insurers, and investment businesses. Its .NET capabilities include C#, current .NET versions, Azure, microservices, backend services, and dedicated developer placement.
This industry focus makes Itexus more suitable for financial products than for a basic corporate website. Typical project areas include mobile banking, digital wallets, trading systems, lending software, financial process automation, and product modernization. The company supports full development cycles as well as team extension and lists US operations in Miami.
Apriorit handles technically demanding .NET projects, including cloud platforms, device management systems, telemetry products, enterprise applications, and software that connects web interfaces with lower-level components. Its services span discovery, architecture, frontend and backend development, API integration, security testing, and maintenance.
The company is a reasonable candidate for products where security, infrastructure, or system performance matters as much as the interface. Apriorit also works on application modernization, helping teams analyze and update older .NET codebases. Its US office is located in Massachusetts.
ScienceSoft develops custom .NET applications from its US headquarters in the Dallas area. Its Microsoft services cover C#, ASP.NET, web portals, cloud applications, APIs, enterprise systems, application modernization, and outsourced .NET development.
The company also provides cybersecurity, data analytics, infrastructure management, help desk support, and quality assurance. This makes it suitable for organizations that want one provider to build a web application and then help operate or secure the surrounding environment. Its experience spans healthcare, finance, manufacturing, retail, and other regulated or process-heavy sectors.
Belitsoft provides custom .NET engineering and staff augmentation from offices in the United States and Europe. Its developers build backend systems, cloud applications, SaaS products, APIs, and browser-based software using C#, ASP.NET Core, .NET, Blazor, and Microsoft Azure.
The company also works with REST, GraphQL, gRPC, SignalR, Docker, and Kubernetes, which is useful for projects involving distributed services or real-time features. Engagements can cover a complete application or provide individual developers for an existing team. Belitsoft maintains a US office in Alexandria, Virginia.
Inoxoft develops .NET Core applications for startups and established companies. Its teams handle product discovery, UI/UX design, backend and frontend engineering, quality assurance, cloud deployment, and ongoing improvement.
The company uses .NET for enterprise software, web platforms, APIs, and scalable backend services. It also offers Python, Node.js, mobile development, AI, and data engineering when a project requires a mixed technology stack. Published industry areas include healthcare, education, logistics, real estate, and finance. Inoxoft lists offices in Philadelphia and Newark, Delaware.
Integrative Systems focuses on Microsoft .NET and IBM i technologies. Its .NET offering includes consulting, custom application development, ASP.NET solutions, web applications, migration, integration, maintenance, and developer augmentation.
This combination is particularly relevant to companies connecting newer browser-based applications with established enterprise systems. Businesses can hire a complete project team or add individual .NET specialists to internal delivery groups. Integrative Systems is based in the Chicago area and serves clients throughout the United States and Canada.
Itransition provides .NET engineering for web applications, SaaS products, enterprise platforms, and cloud-based systems. Its Microsoft practice covers C#, ASP.NET, .NET, Azure, Dynamics 365, application migration, and ongoing support.
The company is geared toward substantial projects involving several business processes or integrations. Services extend into ERP, CRM, ecommerce, data analytics, DevOps, and quality assurance, allowing .NET applications to be developed as part of a broader transformation program. Itransition lists a US office in Decatur, Georgia.
Emergent Software is a Microsoft-focused technology consultancy offering custom software, Azure cloud services, data engineering, AI, security, and managed support. Its development teams use technologies such as C#, .NET, SQL Server, Azure, and the Umbraco content management system.
The company is a strong fit for organizations committed to Microsoft infrastructure and looking for a provider that can work across application and cloud layers. Projects may involve new web software, replacement of older applications, data platforms, CMS development, or ongoing system management. Emergent Software is based in Minneapolis and works with clients across the United States.
Chetu develops custom software and supplies on-demand developers across a wide range of technologies, including .NET and C#. Its teams build web applications, enterprise systems, APIs, cloud software, ecommerce platforms, and industry-specific products.
The company is suited to businesses that want a larger outsourcing provider with multiple technology practices and flexible staffing options. Beyond development, Chetu offers integration, migration, quality assurance, implementation, and ongoing support. Its industry coverage includes healthcare, finance, hospitality, construction, retail, and transportation. The company’s headquarters is in Sunrise, Florida.
The right .NET partner depends less on the longest service list and more on the problem being solved. Some companies here are well suited to complex enterprise modernization, while others make more sense for a new SaaS product, an Azure migration, or a team that simply needs a few experienced C# developers.
Before settling on one provider, look closely at its recent .NET work, preferred engagement model, and experience with systems similar to yours. A short technical discussion often reveals more than a polished portfolio. The best fit will understand the existing architecture, ask sensible questions early, and build software that remains manageable long after the first release.
