As a contractor, I frequently browse software engineering job postings on platforms such as Indeed and LinkedIn. Over the years, I’ve noticed a concerning trend: Microsoft .NET does not seem to appear in job listings as often as it once did. That observation made me curious about which companies are still actively investing in .NET—and, more importantly, what they are actually building with it.
That question led to this article.
Rather than simply listing companies that mention C# or .NET somewhere in their technology stack, I wanted to dig deeper. Wherever possible, I researched how these organizations are using .NET in real-world production systems. The results demonstrate just how diverse the platform remains.
The companies below are using Microsoft .NET for everything from financial systems, healthcare applications, payment processing, insurance platforms, and e-commerce to real-time applications, APIs, microservices, cloud-native services, AI-powered solutions, distributed systems, and large-scale application modernization. Some are running modern .NET 8 and .NET 10, while others are actively migrating legacy .NET Framework applications to the latest versions of the platform.
That matters.
.NET is not simply a technology of the past that survives inside aging enterprise applications. These companies demonstrate that it continues to power modern, business-critical software used by millions of customers, employees, and organizations around the world.
As developers, architects, technology leaders, and customers, we can help reinforce the value of .NET by supporting organizations that continue to invest in the platform—whether by purchasing their products and services, considering them as employers, recommending them within our professional networks, or simply recognizing the engineering work they are doing with Microsoft technologies.
Below is my growing list of companies that use Microsoft .NET, along with details about how they are putting it to work.
If you know of another company that belongs on this list—or you have firsthand knowledge about how one of these organizations uses .NET—please share it in the comments. I’d especially like to hear about specific applications, platforms, architectures, or workloads built with .NET.
Let’s shine a spotlight on the companies that continue to build, innovate, and rock with .NET!
Companies That Use .NET
Alaska Airlines
Alaska Airlines is a major U.S. airline and a subsidiary of Seattle-based Alaska Air Group, which also includes Hawaiian Airlines and Horizon Air. Together, the group serves more than 140 destinations across North America, Latin America, Asia, the Pacific, and Europe.
Alaska Airlines has used Microsoft .NET Core to build software supporting critical airline operations. Alaska engineers developed a custom .NET Core eventing engine used to create realistic, repeatable testing and training environments for the airline’s Weight & Balance system. The system simulates the lifecycle of an entire day of flight operations, including aircraft events, passenger activity, departures, arrivals, delays, and cancellations.
The .NET application integrates with numerous airline systems and executes REST/JSON and SOAP/XML web services, SQL operations, stored procedures, and message-queue events. Alaska reported that the resulting environment was also used to train more than 6,500 frontline employees and played an important role in the integration of Alaska Airlines and Virgin America’s passenger-service systems.
There is also evidence that .NET remains part of Alaska’s modern software stack. A 2026 Senior Software Engineer – Identity & Access Management position sought engineers experienced with .NET Web API and .NET Core, alongside cloud computing, distributed systems, Kubernetes, DevOps, and full-stack application development.
Ardent Mills
Ardent Mills is a leading North American flour-milling and ingredient company producing flour, grains, pulses, organic ingredients, and gluten-free products. The company operates more than 40 locations and supplies ingredients to food manufacturers, bakeries, restaurants, and other customers throughout North America.
Ardent Mills uses Microsoft .NET and C# as part of its enterprise software development stack. Recent technical positions at the company specifically identify .NET, C#, Angular, and SQL as technologies used to develop and maintain its software products. Ardent Mills also employs engineers to perform automated testing of applications built on the Microsoft .NET, Angular, and SQL Server stack.
Microsoft technologies are deeply integrated into Ardent Mills’ IT environment. The company’s IT organization supports approximately 37 business applications, all hosted in Microsoft Azure, while Microsoft has documented Ardent Mills’ use of Power Apps, Power Automate, Dataverse, and Power BI to digitize operations and replace manual, paper-based processes in its mills.
Although Ardent Mills does not publicly identify which individual business applications are written in .NET, its current technical hiring requirements provide direct evidence that .NET and C# are actively used to build and maintain enterprise software and digital platforms within the company.
Unfortunately, Ardent Mills pays developers below-market rates
Aveanna Healthcare
Aveanna Healthcare is a U.S. home-healthcare provider offering private-duty nursing, home health and hospice care, pediatric therapy, personal care, and medical solutions. Its technology supports caregivers working in patients’ homes as well as the clinical, regulatory, and administrative systems required to coordinate that care.
Aveanna uses Microsoft C# and .NET to build healthcare applications and system integrations, particularly around Electronic Visit Verification (EVV) and Medicaid compliance. Recent Aveanna engineering work includes C#/.NET services that automate missed-visit reporting for Medicaid programs in Florida and Pennsylvania, eliminating hundreds of hours of manual data entry each week across more than 60 cost centers.
Aveanna has also used C#/.NET and MySQL to build a caregiver-tracking system supporting Arizona AHCCCS regulatory requirements. Its .NET applications participate in asynchronous cloud workflows using technologies such as AWS SNS, SQS, database triggers, APIs, Terraform, and feature flags, demonstrating .NET’s role in integrating healthcare, compliance, and cloud systems.
Beyond these .NET applications, Aveanna has invested heavily in integrating its clinical technology. Its systems connect electronic medical records, Workday, clinical applications, Active Directory, and Aveanna’s custom EVV platform to exchange caregiver, patient, physician, diagnosis, visit, and time-tracking information.
Unfortunately, Aveanna Healthcare pays developers below-market rates
Carnival Cruise Line
Carnival Cruise Line is one of the world’s largest cruise brands, operating vacation ships that combine accommodations, dining, entertainment, retail, and other guest services. Carnival’s technology infrastructure must support both shoreside operations and highly distributed systems running aboard its ships around the world. Carnival Corporation, its parent company, also uses Microsoft Azure and Azure Arc to extend cloud management and computing capabilities to its fleet.
Carnival Cruise Line has used Microsoft .NET, .NET Core, and C# to develop and maintain shipboard Point-of-Sale (POS) applications used aboard its vessels. Public engineering experience from Carnival identifies technologies including C#, .NET Core, WPF, WCF, Web API, SQL Server, Oracle, and Azure DevOps as part of these systems.
.NET has also been used in Carnival’s payment-processing infrastructure. Engineering work at the company included converting Java-based payment-processing APIs to .NET Core, as well as building automated scheduled processes with the .NET Framework and C#. These applications integrate with databases, REST-style Web APIs, and other shipboard systems.
Carnival has additionally relied on Sitecore for customer-facing digital experiences and personalization. Sitecore has publicly identified Carnival Cruise Lines as one of the major brands using its digital experience platform.
Together, these examples show Microsoft .NET being used at Carnival for onboard retail and POS systems, payment processing, APIs, automation, and enterprise integration, while Microsoft Azure supports Carnival’s broader cloud-to-ship technology infrastructure.
Unfortunately, Carnival Cruise Line pays developers below-market rates
Crate & Barrel
Crate & Barrel is a major home furnishings retailer offering furniture, housewares, décor, kitchen products, and related merchandise through its stores and e-commerce platforms. The company operates a substantial technology organization responsible for the digital and enterprise systems supporting its retail, e-commerce, supply-chain, and fulfillment operations.
Crate & Barrel uses Microsoft C# and .NET to develop APIs, microservices, and enterprise integration services. A 2026 Software Engineer position for the company’s Enterprise Item team specifically requires proficiency in C# and .NET for systems that manage the flow of product, pricing, availability, and content data between enterprise systems and customer-facing applications.
These .NET-based services operate within a modern distributed architecture involving REST APIs, microservices, cloud platforms, CI/CD pipelines, SQL and NoSQL databases, and DevOps practices. They help ensure that product information and inventory-related data can reliably move between Crate & Barrel’s internal systems and the applications used by customers.
Crate & Barrel is also modernizing its e-commerce fulfillment infrastructure around event-driven architectures, distributed state machines, message brokers, real-time inventory visibility, and order-routing systems. Its current engineering requirements specifically identify .NET/C# as one of the enterprise backend ecosystems used for building high-scale, fault-tolerant microservices supporting this environment.
Crate & Barrel therefore provides a good example of Microsoft .NET being used in large-scale retail for product-data management, APIs, microservices, enterprise integration, inventory visibility, and e-commerce fulfillment.
Unfortunately, Crate & Barrel pays developers below-market rates
https://www.crateandbarrel.com
Crysta_code
CrystaCode is an AI platform that allows businesses and individuals to create and publish customized AI agents through a conversational interface. Instead of requiring users to write code or configure complex workflows, users describe what they want their AI agent to do, customize it, and publish it for real-world use.
CrystaCode is built extensively with Microsoft .NET and C#. Its user interface uses Blazor, while SignalR provides real-time communication between the browser and server. This allows CrystaCode’s AI agents to do more than simply generate text—for example, an agent can invoke server-side functions that cause the Blazor interface to navigate, display information, open dialogs, or change application settings in real time.
The platform also uses Microsoft’s modern AI stack, including Microsoft.Extensions.AI, Microsoft.Extensions.AI.OpenAI, and Azure.AI.OpenAI. CrystaCode integrates the Model Context Protocol (MCP) with its .NET architecture, allowing AI agents to discover and execute external tools for capabilities such as scheduling, reservations, business-data access, and other integrations.
CrystaCode CEO Mehran Davoudi has described the platform’s architecture as using Blazor with Bit Platform for reusable UI components, SignalR for real-time communication, Microsoft.Extensions.AI abstractions for AI-provider integration, and Azure OpenAI for AI services.
CrystaCode provides an excellent example of modern Microsoft .NET being used to build a production AI-agent platform, combining Blazor, C#, real-time communications, function calling, MCP integrations, and Azure-based artificial intelligence.
DuckDuckGo
DuckDuckGo is an online privacy company best known for its privacy-focused search engine and browser. Its browser is available on Windows, macOS, iOS, and Android and includes built-in protections designed to reduce online tracking and the collection of personal information.
DuckDuckGo uses Microsoft C# and .NET 8 to develop its Windows desktop browser. Engineers on its Windows team work with C#, .NET 8, WPF, WebView2, Git, and Visual Studio to build secure, privacy-focused Windows applications.
DuckDuckGo has identified specific .NET development projects for its Windows browser, including improving browser startup performance and implementing bookmark and login exporting. Its Windows architecture also makes use of familiar .NET application patterns and technologies such as MVVM, MVP, and Rx.NET.
The .NET-based Windows application integrates WebView2 for web content while C# and .NET provide the surrounding native desktop application and functionality. DuckDuckGo describes the Windows browser as one of its flagship products, with its engineering team responsible for developing major customer-facing features and the software architecture supporting them.
DuckDuckGo provides an excellent example of modern .NET being used to build a mainstream consumer desktop application, demonstrating that C# and .NET are well suited not only for enterprise back-end systems but also for privacy-focused, customer-facing Windows software used by millions of people.
eBay
eBay is one of the world’s largest online marketplaces, connecting buyers and sellers across a global e-commerce platform.
eBay uses Microsoft C# and .NET to develop internal applications used by its global customer-support organization. In 2026, eBay specifically recruited .NET engineers for its Agent Desktop team, which builds the core tools used by customer-support agents. These desktop applications are developed with C#, .NET, and WPF and provide workflows that help agents deliver customer service efficiently.
The .NET Agent Desktop applications integrate with eBay’s backend systems through REST and SOAP APIs using JSON and XML, while engineers also build automated unit and integration tests and participate in CI/CD and production releases.
eBay also develops and publishes official .NET libraries for developers integrating with the eBay platform. Its open-source eBay OAuth C# Client Library targets .NET and simplifies obtaining and managing OAuth 2.0 access tokens when calling eBay REST APIs. The library is distributed as a NuGet package and eBay’s current repository builds it for .NET.
In addition, eBay publishes an Event Notification SDK for .NET, providing developers with a .NET implementation for receiving, validating, and processing eBay marketplace event notifications. The SDK demonstrates how .NET applications can securely receive HTTPS notifications, verify their signatures, and route them to custom message-processing code.
eBay therefore provides a strong example of Microsoft .NET being used both internally for business-critical customer-support applications and externally as part of the developer ecosystem surrounding its APIs, authentication, and event-notification services.
Experian
Experian is a global data and technology company providing services in credit reporting, fraud prevention, identity verification, healthcare, automotive data, marketing, and financial services. Its software platforms process and analyze large volumes of data to help businesses assess risk, verify identities, prevent fraud, and make data-driven decisions.
Experian uses Microsoft C# and .NET extensively across its software portfolio. Its current engineering requirements include C#, .NET, API development, cloud-native architectures, SQL databases, Docker, Kubernetes, CI/CD, and AWS services such as Lambda, API Gateway, SQS, DynamoDB, and EKS. Experian engineers use these technologies to build scalable application components, services, and APIs—including APIs that integrate machine-learning models and data-driven capabilities into customer-facing applications.
A particularly specific example is Experian Health, where .NET is used in its Medical Necessity, Authorization, and Notice of Care product suites. These healthcare systems use technologies including C#, VB.NET, ASP.NET, .NET Core, .NET 8, SQL Server, REST and SOAP services, React, AWS, Docker, Kubernetes, and Terraform. Experian is also actively modernizing older .NET Framework applications alongside newer .NET 8 services.
Within Experian Employer Services, Microsoft .NET and Azure are used to develop high-volume, high-transaction applications. The technology stack includes C#, .NET Framework, SQL Server, Entity Framework, APIs, microservices, containers, Azure cloud services, and Azure DevOps CI/CD pipelines.
Experian therefore provides an excellent example of Microsoft .NET being used at enterprise scale for healthcare applications, APIs and microservices, cloud-native services, data processing, machine-learning integration, and high-volume transactional systems.
Experian Block hires Microsoft MVP’s!
First American Home Warranty
First American Home Warranty provides home warranty plans covering the repair or replacement of major household systems and appliances. The company has served homeowners for more than 40 years and provides online services that allow customers to manage their plans, request service, and track claims.
First American Home Warranty uses Microsoft C# and .NET 8 to develop and maintain its business applications. Recent engineering requirements specifically call for developers to build full-stack web applications using C#, .NET 8, React, and TypeScript.
Its .NET developers build scalable RESTful Web APIs that integrate with backend databases and other services. The company’s engineers are also responsible for designing multi-tier application architectures, developing internal business systems, maintaining production applications, implementing automated testing, and supporting CI/CD pipelines.
The technology stack combines .NET 8 on the backend with React and TypeScript on the frontend, demonstrating the common modern architecture of using ASP.NET-based APIs and services alongside a JavaScript front-end framework.
First American Home Warranty therefore provides a good example of modern Microsoft .NET being used to build web applications, APIs, business systems, database integrations, and customer-facing digital services supporting the home warranty industry.
https://homewarranty.firstam.com
GEICO
GEICO is one of the largest automobile insurers in the United States and a member of the Berkshire Hathaway family of companies. Its technology organization develops consumer and business insurance products, claims experiences, enterprise systems, data platforms, and hybrid-cloud infrastructure.
GEICO uses Microsoft C# and .NET to build modern insurance applications and distributed services. Current GEICO engineering positions specifically seek developers specializing in .NET and C# to design scalable, resilient distributed systems, APIs, microservices, and cloud-based applications.
A particularly clear example is GEICO’s Underwriting Engineering organization. Its engineers use .NET to develop applications that streamline underwriting processes and improve decision-making. GEICO’s Underwriting Automation team is also developing AI-enabled systems designed to reduce repetitive manual work and help underwriters work faster and more accurately. These systems use API-first architectures, microservices, event-driven processing, messaging, GraphQL, gRPC, databases, Docker, Kubernetes, and cloud services.
GEICO also recruits engineers specifically for C#, microservices, and Microsoft Azure, reflecting the role Microsoft technologies play in the company’s ongoing modernization from traditional IT systems toward cloud-native, high-availability platforms.
GEICO therefore provides an excellent example of Microsoft .NET being used in the insurance industry for underwriting systems, AI-assisted automation, APIs, microservices, distributed applications, and cloud-based enterprise platforms.
H&R Block
H&R Block is a tax-preparation and financial-services company serving millions of individuals and small businesses through retail offices and digital tax-filing products.
H&R Block uses Microsoft .NET to build customer-facing tax applications and backend services. One of the clearest examples is AI Tax Assist, H&R Block’s generative AI-powered tax preparation assistant. The company deliberately chose .NET to build the solution, integrating it with Microsoft Azure, Azure OpenAI Service, Azure App Service, and Azure Functions.
AI Tax Assist allows customers to ask tax questions conversationally while preparing their returns and receive assistance related to tax forms, deductions, credits, and changing tax laws. H&R Block’s Principal Architect has explained that the company selected .NET because its engineering teams already had significant experience with the platform and could use the same architectural patterns and technologies while incorporating generative AI.
Scalability is particularly important because H&R Block must support millions of users during peak tax season. The combination of .NET and Azure provides the performance, reliability, security, and scalability required to operate AI Tax Assist under those seasonal workloads.
H&R Block continues to use C# and .NET for backend services and data systems. Current engineering positions involve developing and maintaining C#/.NET services and SQL Server data models supporting the company’s applications.
H&R Block therefore provides an excellent example of Microsoft .NET being used for high-scale consumer applications, AI-assisted tax preparation, cloud-native services, APIs, data processing, and Microsoft Azure integration.
H&R Block hires Microsoft MVP’s!
Unfortunately, H&R Block pays developers below-market rates
Hilton Hotels
Hilton is one of the world’s largest hospitality companies, with 27 hotel brands and more than 9,200 locations worldwide. Its digital ecosystem supports hotel reservations, Hilton Honors, guest services, corporate operations, and applications used across its global hospitality network.
Hilton uses Microsoft C# and .NET within its enterprise software environment. In a recent Hilton Software Engineer position, the company specifically identified .NET and C# as technologies used to develop new business-automation capabilities and enhance existing automation solutions. These systems are part of Hilton’s Corporate Systems technology organization and work alongside automation platforms such as Blue Prism.
Hilton has also used C# and .NET Core for web application development. Hilton’s own Web Developer requirements have included C# .NET Core Web APIs, C# .NET MVC, REST APIs, React, SQL Server, and Entity Framework, demonstrating .NET’s use for backend web services, APIs, database access, and integration with modern frontend applications.
Microsoft .NET has additionally appeared in Hilton’s enterprise infrastructure automation, including development associated with Microsoft 365, Exchange, Teams, SharePoint, Active Directory, and Azure environments. Hilton has sought engineers experienced in developing automation code using .NET and PowerShell for these systems.
Hilton therefore provides a good example of Microsoft .NET being used in the hospitality industry for enterprise automation, web APIs, backend web applications, database integration, and Microsoft-platform infrastructure management.
Labcorp
Labcorp is a global healthcare and life-sciences company providing diagnostic laboratory testing and drug-development services to physicians, hospitals, pharmaceutical companies, researchers, and patients. Its laboratory network and technology platforms support healthcare decisions and large-scale clinical and laboratory operations.
Labcorp uses Microsoft .NET and C# to develop mission-critical laboratory software. In 2026, Labcorp sought software engineers with extensive experience in .NET Core, ASP.NET, MVC, WCF, and Entity Framework to design, develop, and support systems responsible for complex clinical and operational laboratory workflows.
One particularly interesting area is Labcorp’s internally developed Virtual LIMS (Laboratory Information Management System). Engineers responsible for this system work with .NET technologies, SQL Server, APIs, microservices, Docker, Kubernetes, distributed messaging technologies such as Kafka and RabbitMQ, and cloud platforms including Microsoft Azure. The software supports laboratory operations and clinical workflows while Labcorp continues migrating legacy systems to more modern platforms.
Labcorp also uses C# and .NET in pre-analytical laboratory processes, including applications supporting specimen accessioning, Patient Service Centers (PSC), and In-Office Phlebotomy (IOP). These applications integrate .NET with REST APIs, Kafka, message queues, relational databases, Angular, and other enterprise technologies. Labcorp is actively moving some of these traditional thick-client applications toward modern, cloud-based architectures.
Another example is Labcorp’s work with Laboratory Information Management Systems (LIMS) such as Thermo Fisher SampleManager, where its development requirements include C# and .NET for application development, enhancement, integration, and global laboratory operations.
Labcorp therefore provides an excellent example of Microsoft .NET being used in healthcare for laboratory information systems, specimen-processing workflows, clinical applications, APIs and microservices, distributed systems, and cloud modernization.
Unfortunately, LabCorp pays developers below-market rates.
LandLogic
LandLogic is a Canadian technology company that provides an AI-powered property and land intelligence platform. Its solutions aggregate and standardize zoning, planning, real estate, and geospatial data to help developers, real estate professionals, municipalities, and property owners evaluate sites, understand development potential, perform due diligence, and make faster land-use decisions. LandLogic also provides APIs and AI-powered tools that allow its property intelligence to be integrated into other platforms.
There is evidence that Microsoft .NET Core has been used in the development of LandLogic’s technology. A former LandLogic Lead Software Engineer who worked on its GIS platform publicly lists .NET Core and SQL Server among his technologies. That GIS platform reportedly incorporated more than 2,000 GIS layers and over 500 datasets. While LandLogic does not currently publish a detailed technology stack, this provides a reasonable indication that .NET has been used within its software platform.
McDonald’s
McDonald’s is one of the world’s largest restaurant companies, operating a massive global digital ecosystem supporting customers, restaurant crews, franchisees, delivery, Drive Thru, ordering, and corporate operations. McDonald’s says its technology organization supports digital experiences used by more than 65 million customers each day.
McDonald’s uses Microsoft C# and .NET extensively within its enterprise software environment. Current McDonald’s engineering teams develop and maintain applications using .NET Framework 4.8, ASP.NET MVC, and modern .NET 8 and .NET 10.
One specific example is McDonald’s customer feedback and support platform. Engineers working on this platform use C# and .NET to develop enterprise applications, RESTful APIs, and backend services while simultaneously modernizing legacy .NET Framework applications to current versions of .NET. These systems support users across McDonald’s global operations.
McDonald’s also uses C#, ASP.NET, Web API, .NET Core, and .NET Framework to develop microservices applications. Its engineering organization combines these technologies with modern CI/CD systems such as Azure DevOps and GitHub Actions, while supporting products deployed across McDonald’s global markets.
Microsoft technologies also play an important role in McDonald’s cloud and identity infrastructure. McDonald’s engineers work with .NET Core, C#, Azure Functions, Azure Kubernetes Service, Azure Service Bus, Event Grid, Cosmos DB, API Management, and Microsoft Entra ID to build secure distributed applications and identity-and-access-management solutions.
McDonald’s therefore provides an excellent example of Microsoft .NET operating at enormous global scale for enterprise applications, customer-support platforms, REST APIs, microservices, cloud services, identity systems, and application modernization.
Moody’s Corporation
Moody’s Corporation is a global financial-services company providing credit ratings, research, data, analytics, and risk-management solutions. Through Moody’s Ratings and Moody’s Analytics, the company helps financial institutions, corporations, governments, and investors evaluate credit, financial, compliance, and other forms of business risk.
Moody’s uses Microsoft C# and .NET Core to develop business-critical financial applications and backend services. Its current engineering teams build production systems using C#/.NET Core along with SQL and NoSQL databases, Microsoft Azure, AWS, CI/CD pipelines, and modern distributed-system architectures.
One particularly interesting use case is structured finance. Moody’s engineers use C# and .NET to develop and support applications that acquire, process, enrich, and maintain financial data used in waterfall cash-flow modeling for securitized products such as CMBS, ABS, and RMBS. These systems include desktop, UI, and console components as well as scalable data-extraction tools, ETL pipelines, and serverless workloads running on Azure and AWS.
Moody’s also uses C# and .NET Core for scalable REST APIs and microservices within Moody’s Analytics. Its Data Estate Engineering teams build secure APIs, microservices, and real-time event-driven data pipelines using technologies such as Apache Kafka, Docker, Kubernetes, relational and NoSQL databases, OAuth, OpenID Connect, and JWT authentication. These systems form part of Moody’s next-generation data infrastructure used to deliver timely financial and risk data across its products.
Moody’s therefore provides an excellent example of Microsoft .NET being used in financial services for structured-finance applications, financial-data processing, REST APIs, microservices, ETL pipelines, event-driven systems, desktop applications, and cloud-native workloads.
One Ontario
One Ontario is a Canadian nonprofit organization working to modernize Ontario’s fragmented planning, building-permit, and development-approval processes. Its goal is to create a standardized, province-wide digital permitting system that connects municipalities, developers, government agencies, and other stakeholders, reducing duplication and accelerating housing development.
In 2026, One Ontario began developing a province-wide AI-enabled permitting platform and selected LandLogic as its technology partner. LandLogic’s property intelligence and Parcella AI technology are being incorporated into the platform to help users identify permitting requirements, check compliance, prepare submissions, and track approval workflows.
While One Ontario does not publicly document the platform’s complete software stack, LandLogic—the organization responsible for the technology behind the platform—has used Microsoft .NET technologies in its software development. This makes One Ontario an example of .NET being used indirectly to support the modernization of government permitting and land-development workflows.
O’Reilly Auto Parts
O’Reilly Auto Parts is one of the largest automotive aftermarket retailers in North America, selling replacement parts, tools, supplies, equipment, and accessories to both professional service providers and do-it-yourself customers. As of June 30, 2026, O’Reilly operated 6,695 stores across the United States, Puerto Rico, Mexico, and Canada.
O’Reilly Auto Parts has used Microsoft C# and .NET within its software-development organization. Public engineering profiles from O’Reilly developers identify technologies including C#, ASP.NET MVC, ASP.NET Web API, WCF, SQL Server, and .NET Core as part of their professional work.
One recent O’Reilly software engineer who worked at the company from 2023 through July 2026 describes developing C#/.NET Core Web APIs for RESTful services, providing evidence that modern .NET has been used for backend APIs and application integration within O’Reilly’s technology environment.
O’Reilly operates a large digital and enterprise technology ecosystem supporting e-commerce, retail stores, product information, inventory, distribution, APIs, and business applications. Its current engineering organization is also investing heavily in microservices, API gateways, Kafka messaging, and Google Cloud Platform, demonstrating a heterogeneous technology environment rather than one built exclusively around .NET.
O’Reilly Auto Parts therefore provides an example of Microsoft .NET being used for backend services, REST APIs, web applications, and enterprise software integration within a large automotive retail organization.
Unfortunately, O’Reilly pays developers below-market rates
Paylocity
Paylocity is a cloud-based human capital management (HCM) software company providing an integrated platform for payroll, human resources, time and labor, benefits, talent management, employee experience, finance, and IT. Its software helps organizations automate workforce processes while giving employees and managers access to HR and payroll services through a unified platform.
Paylocity uses Microsoft C# and .NET extensively in its core software platform. Current engineering teams work with multiple .NET frameworks, including .NET Core, along with C#, SQL Server, MongoDB, PostgreSQL, REST-style APIs, messaging systems, React, Docker, and cloud infrastructure.
One particularly important use of .NET is Paylocity’s Time Management platform. This system handles high volumes of employee time data and complex business and regulatory rules. The data managed by these applications directly affects payroll accuracy, regulatory compliance, and customer trust. Paylocity’s engineers use C# and .NET Core to build and maintain these high-transaction systems and their domain APIs.
Paylocity is also actively modernizing its .NET applications, moving Time Management functionality out of a monolithic architecture and into a more modern platform. The modernization effort focuses on scalability, reliability, observability, API quality, and reducing technical debt while protecting critical time and payroll calculations.
.NET is used elsewhere across Paylocity’s product organization as well. Its Community engineering team requires strong .NET and C# skills alongside RabbitMQ-style messaging, MongoDB, AWS, and production observability tools. Paylocity’s Search & AI Assistant organization also uses C#/.NET for backend development, combined with React, distributed systems, APIs, high-volume data processing, and conversational AI technologies.
Paylocity therefore provides an excellent example of Microsoft .NET being used to build high-volume payroll and time-management systems, backend APIs, distributed services, employee-experience applications, and AI-enabled enterprise software.
Peloton Interactive
Peloton Interactive is a connected-fitness and technology company combining internet-connected exercise equipment, digital applications, instructor-led fitness content, and subscription services. Peloton serves a global community of millions of members through its fitness platform.
Peloton uses Microsoft C# and .NET within its software engineering organization. Public engineering experience from Peloton documents C#/.NET alongside technologies including React, TypeScript, MongoDB, Kafka, RabbitMQ, AWS, and Google Cloud.
One particularly interesting use of .NET technology is Peloton’s internal Programming Tool, which helps manage instructor schedules and content-production workflows. Peloton engineers have used SignalR with MongoDB Change Streams to provide real-time collaboration, allowing multiple users to edit instructor schedules simultaneously while handling race conditions between API responses and real-time events.
The system also uses Kafka-based event-driven processing to synchronize pre-production programming schedules with downstream post-production systems. Peloton additionally operates music-related APIs and services supporting instructor workflows, music data, and royalty reporting.
Peloton therefore provides a good example of Microsoft .NET being used for real-time applications, internal scheduling and production tools, APIs, event-driven systems, and enterprise workflow software within a large connected-fitness platform.
Previato Software
Previato Software is a Brazilian software development company specializing in custom web applications, APIs and integrations, Windows desktop software, automation, and cloud-based solutions. The company uses Microsoft .NET 10 and Blazor to build full-stack web applications and also uses Microsoft Azure as part of its cloud infrastructure.
One of its primary products is Medwizard, a medical software platform designed for clinics that perform imaging procedures such as endoscopy. Medwizard manages scheduling, patient records, structured medical reports, image capture and annotation, automatic PDF report generation, and delivery of reports to patients through WhatsApp.
The system also includes a Windows desktop application called Medwizard Capture, which connects directly to imaging equipment to capture procedure images. It can operate offline if an internet connection is interrupted and automatically synchronizes captured images when connectivity returns.
Previato Software provides a particularly good real-world example of Blazor and .NET being used to build a complete commercial healthcare application, combining a cloud-based web platform, Windows desktop software, medical-image handling, document generation, APIs, and Microsoft Azure.
https://previatosoftware.com.br
Progressive
Progressive Insurance is one of the largest insurance companies in the United States, offering automobile, commercial vehicle, motorcycle, boat, recreational vehicle, homeowners, renters, and other insurance products. Its technology organization develops and supports applications used by customers, insurance agents, and employees.
Progressive uses Microsoft C# and .NET to develop full-stack applications, web services, backend systems, and enterprise integrations. Recent Progressive engineering positions specifically require experience with C#, .NET, JavaScript, RESTful APIs, and modern web-development technologies.
One current example is Progressive’s Mergers and Acquisitions integration technology. A July 2026 Senior IT Software Developer in Test position calls for C# and .NET experience to build and test integration capabilities supporting Progressive’s M&A initiatives. The technology stack includes .NET Framework, Angular, RestSharp, MSTest, Reqnroll, Git/GitHub, and CI/CD pipelines.
.NET is also used in Progressive’s automated testing environment. Engineers create automated tests for APIs and user interfaces and perform regression, performance, stress, and other forms of software testing. These systems operate alongside AWS technologies including SQS, SNS, Lambda, and S3.
Progressive’s broader technology organization develops custom applications supporting areas such as claims reporting, mobile applications, AI and chatbot systems, and other insurance operations, although Progressive does not publicly identify which of these individual applications are built specifically with .NET.
Progressive therefore provides a strong example of Microsoft .NET being used in the insurance industry for full-stack applications, backend services, REST APIs, enterprise integration, automated testing, and cloud-connected systems.
Unfortunately, Progressive pays developers below-market rates.
S&P Global
S&P Global is a global financial information and analytics company providing credit ratings, market intelligence, benchmarks, financial data, and risk and workflow solutions. Its businesses include S&P Global Market Intelligence, S&P Global Ratings, S&P Global Energy, and S&P Dow Jones Indices.
S&P Global uses Microsoft C# and .NET extensively across its financial software platforms. Current engineering teams develop applications using C#, .NET Core, ASP.NET, REST APIs, microservices, SQL Server, cloud platforms, containers, and modern CI/CD practices.
One particularly strong example is S&P Global’s Municipal Bond Issuance platform. Engineers use .NET, C#, ASP.NET, Angular, SQL Server, and AWS to develop systems supporting critical workflows throughout the municipal bond issuance lifecycle. S&P Global is modernizing these applications using API-first design, microservices, event-driven architectures, and cloud-native development practices.
.NET is also used within S&P Dow Jones Indices, where engineering teams develop and support applications using Microsoft .NET, C#, MVC web applications, SQL Server, and other database technologies. These systems support the technology organization responsible for S&P’s globally recognized financial indices and benchmarks.
Within S&P Global Market Intelligence, full-stack developers use C#, ASP.NET MVC, .NET Core, React, RESTful services, Microsoft Web API, SQL Server, and PostgreSQL to build financial web applications and services.
S&P Global therefore provides an excellent example of Microsoft .NET being used in financial services for capital-markets applications, municipal bond systems, financial indices, web applications, REST APIs, microservices, data processing, and cloud-native enterprise platforms.
S&P Global hires Microsoft MVP’s!
SeatGeek
SeatGeek is a technology company and ticketing marketplace that enables fans to buy and sell tickets for concerts, sports, theater, and other live events. SeatGeek also provides primary box-office and ticketing technology for professional sports teams, venues, and entertainment organizations.
SeatGeek uses Microsoft C# and .NET to build business-critical ticketing systems. One of its most important .NET projects is SeatGeek Open, an integration platform connecting SeatGeek’s consumer marketplace and distribution partners with the box-office systems operated by teams and venues. SeatGeek specifically chose C# and .NET Core because of its performance, scalability, Linux support, and compatibility with an existing .NET Framework-based ticketing platform.
SeatGeek Open was built as a .NET Core application running in Linux Docker containers and uses PostgreSQL with Entity Framework. The platform communicates with ticketing systems through large, strongly typed APIs and supports critical operations such as purchasing tickets, managing ticket inventory, and scanning tickets as fans enter venues. SeatGeek reported that the system successfully handled a 19,000-person Sporting Kansas City event during its initial deployment.
SeatGeek also runs .NET-based ticketing applications on Amazon Web Services, using services such as Amazon EC2, Windows Server, and Microsoft SQL Server. AWS has documented SeatGeek’s use of .NET Core to provide the scalability and high availability required during major ticket on-sales and large live events, when thousands of fans may attempt to purchase or scan tickets simultaneously.
C# continues to appear in SeatGeek’s modern distributed architecture. SeatGeek’s Data Platform team has developed a C# library for its transactional outbox infrastructure, allowing applications to publish real-time domain events through PostgreSQL, Debezium, Kafka, and the Confluent Schema Registry. The system is designed to maintain data integrity while distributing events such as order and inventory changes across SeatGeek’s services.
SeatGeek therefore provides an excellent example of Microsoft .NET being used for high-scale ticketing platforms, box-office integrations, ticket purchasing and scanning, distributed systems, real-time event processing, and cloud-hosted services.
U-Haul
U-Haul is a North American moving and storage company providing truck and trailer rentals, self-storage, moving supplies, and portable U-Box moving and storage containers. Founded in 1945, U-Haul has grown from a small trailer-rental operation into a large technology-supported network serving customers throughout the United States and Canada.
U-Haul uses Microsoft C# and .NET extensively within its software-development organization. Current engineering teams develop applications with C#, .NET Core, ASP.NET MVC, Web API, SQL Server, PostgreSQL, JavaScript frameworks, and related Microsoft technologies.
One particularly strong example is U-Haul’s Retail Sales Development organization. This team builds and supports both customer-facing web applications and internal tools used to operate U-Haul’s retail-sales business. Its developers use C#, .NET Core, ASP.NET MVC, Web API, SQL, PostgreSQL, Vue, Redis, Kafka, and Azure DevOps.
.NET is also used by U-Haul’s U-Box Software Development Team, which supports critical systems associated with the company’s portable moving and storage container business. These applications use the Microsoft .NET and C# stack together with Kafka event streams and CQRS-based architectures to create scalable and resilient distributed systems. U-Haul developers also work with Azure API Management, SQL Server, PostgreSQL, Elasticsearch/Kibana, Dynatrace, and Grafana.
Microsoft C# and .NET also play a significant role in U-Haul’s automated software testing infrastructure. U-Haul’s current Software Development Engineer in Test organization specifically prefers .NET/C# expertise for building automated testing frameworks using technologies such as Selenium, Appium, and Playwright, with integration into CI/CD and Azure DevOps environments.
U-Haul therefore provides an excellent example of Microsoft .NET being used for customer-facing web applications, retail systems, U-Box logistics software, REST APIs, distributed event-driven systems, and automated testing infrastructure.
Unfortunately, U-Haul pays developers below-market rates
Worldpay LLC
Worldpay is a global payments technology company that provides payment processing, merchant services, e-commerce payments, embedded payments, fraud prevention, and related financial technology for businesses and software platforms. In January 2026, Worldpay became part of Global Payments following the completion of Global Payments’ acquisition of the company.
Worldpay uses Microsoft C# and .NET extensively to build payment-processing and merchant-services applications. Current Worldpay engineering teams develop software using C#, ASP.NET Core, modern .NET, SQL Server, REST APIs, Entity Framework, JavaScript/TypeScript, and cloud technologies.
One particularly strong example is Worldpay’s Launchpad platform, which streamlines the process of onboarding new merchants. Launchpad collects the information required to establish merchant accounts so businesses can begin accepting credit-card payments and settling transactions through Worldpay. The platform includes both a customer-facing user interface and APIs for integration with partner systems.
Worldpay engineers use C#, ASP.NET Core, and modern .NET 8+ to develop Launchpad’s full-stack applications, RESTful APIs, backend services, and system integrations. Worldpay is also modernizing large legacy .NET Framework 4.x applications by migrating them to modern .NET, creating cloud-ready architectures with improved scalability, performance, and maintainability.
.NET is also used within Worldpay’s Alternative Payments engineering organization. Current developers on that team work with Microsoft’s C#/.NET stack, SQL, REST APIs, cloud technologies, Kubernetes, OpenShift, and DevOps practices to build and operate services supporting alternative payment methods and global commerce.
Worldpay therefore provides an excellent example of Microsoft .NET being used in financial technology for merchant onboarding, payment-processing applications, REST APIs, backend services, system integrations, alternative payments, and large-scale application modernization.
Zillow
Zillow is a major U.S. real-estate technology company providing online tools and services for home buying, selling, renting, financing, property valuation, and real-estate professionals. Its ecosystem includes Zillow, Zillow Rentals, Zillow Home Loans, ShowingTime, Follow Up Boss, dotloop, and other real-estate technology products.
Zillow uses Microsoft C# and .NET within its ShowingTime software organization. Zillow acquired ShowingTime, a home-touring and showing-scheduling technology company, in 2021 and later incorporated its capabilities into Zillow’s broader suite of software for real-estate professionals.
In 2026, Zillow specifically recruited senior developers with strong .NET/C# experience building and maintaining production services for the ShowingTime team. These engineers develop backend services and user-facing applications, add new product features, create third-party integrations, and integrate ShowingTime functionality into the Zillow Workspace platform.
The .NET applications operate within a modern distributed architecture incorporating technologies such as Kafka, AWS EKS/ECS/EC2, Docker, Kubernetes, Angular, TypeScript, DynamoDB, relational databases, CI/CD pipelines, and observability platforms. This demonstrates C# and .NET being used alongside cloud-native and event-driven technologies rather than solely in traditional Windows applications.
Zillow has also historically used C# and .NET for large-scale data processing. An official Zillow engineering article documented a C#/.NET clickstream-processing pipeline that parsed and transformed nearly a billion web events per day using .NET multithreading before that particular workload was eventually migrated to Hadoop and later Spark as its data volumes grew.
Zillow therefore provides a good example of Microsoft .NET being used for real-estate scheduling and workflow software, production backend services, third-party integrations, event-driven systems, and cloud-based applications.
Final Thoughts
The companies featured in this article represent only a small sample of the organizations that continue to invest in Microsoft .NET. As we’ve seen, .NET is being used for far more than traditional enterprise applications. These companies are building cloud-native services, APIs, microservices, financial platforms, healthcare systems, AI-powered applications, real-time solutions, e-commerce platforms, distributed systems, and mission-critical business software with Microsoft technologies.
That is something worth supporting.
If you use the products or services offered by these companies, consider supporting the organizations that continue to invest in .NET. If you are looking for your next software engineering opportunity, take a closer look at companies that are actively hiring C# and .NET developers. And if you work with other developers, architects, or technology leaders, help spread the word about organizations that continue to build and innovate with the .NET ecosystem.
The stronger the demand for companies that use .NET, the stronger the incentive is for organizations to continue investing in the platform—and in the engineers who build with it.
I also want this article to continue growing.
If you are a software engineer, architect, engineering manager, or other technology professional working for a company that uses Microsoft .NET, please reach out to me. I would love to include your company in this article, especially if you can share information about how .NET is being used within your organization. Whether your team is building APIs, desktop applications, cloud services, AI solutions, internal business systems, mobile applications, or something completely different, I want to hear about it.
Likewise, if you know of another notable company using .NET, please share it in the comments. The more real-world examples we can document, the better we can demonstrate the continued relevance, versatility, and importance of Microsoft .NET in modern software development.
Let’s support the companies that support .NET—and keep showing the industry just how much incredible software is being built with it. Röck on!
Companies That Don’t Use .NET
While many organizations have adopted Microsoft .NET, there are also some well-known companies that have chosen other technologies for their software development. Here’s a list of companies that currently do not rely on .NET:
- Airbnb
- Angi
- Brooksource
- Capital One
- Caterpillar
- CAVA
- Coinbase
- DICK’s Sporting Goods
- Frontdoor Inc.
- General Motors
- Gerber Life Insurance Company
- H-E-B
- hims & hers
- Home Depot
- Humana
- Liftoff Mobile
- Lowes (does not support remote work)
- Mercury Insurance
- META
- MongoDB
- Netflix (they used to use .NET!)
- Paramount
- Perforce
- Pluralsight
- Reddit, Inc.
- Shutterfly
- SquareSpace
- Stripe
- U.S. News & World Report
- Upstart
- Vimeo
- Wendy’s
- Yahoo
- Yahoo Finance
- Yum! Brands
- The Wendy’s Company
- Zoox
While these companies may not currently use .NET, many are still heavily invested in other technology stacks such as Java, Python, JavaScript, and more. Nonetheless, recognizing the diversity of technologies in use across the industry is important for developers and tech enthusiasts alike.
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