Modernizing .NET applications at scale using AWS with Nol Universe

Nol Universe operates a wide range of travel, ticketing, and leisure services, combining data from multiple systems to deliver personalized experiences. As demand grew, its existing .NET Framework–based applications became harder to maintain and scale. The environment depended on Microsoft Windows infrastructure and required significant manual effort to update or expand. “As our platform grew, we began to run into clear limitations with the .NET Framework, especially around scalability, maintenance, and understanding our legacy systems,” says YoonSeong Ji, senior technical director at Nol Universe.

In addition to technical constraints, the company faced resource challenges. Teams had limited time to dedicate to large-scale modernization initiatives while continuing to support existing services. Recruiting and training developers with expertise in legacy systems added further complexity.

Without a new approach, modernizing millions of lines of code would have taken months and required significant manual effort. Nol Universe needed a faster, more efficient way to move forward while maintaining day-to-day operations, leading the company to use AWS in modernizing its .NET applications at scale.

Nol Universe adopted a strategy that combined automated code transformation with testing and deployment processes. The company used AWS Transform for .NET—the first agentic AI service for modernizing .NET applications at scale—to automate the migration of its legacy applications to a modern, cross-platform environment. The service analyzed dependencies and converted large portions of the codebase in parallel, preparing applications for containerization. This aided Nol Universe in handling complex, interconnected systems and transforming millions of lines of code in a fraction of the time required for manual migration.

To support testing and validation, Nol Universe used Amazon Q Developer—a generative AI–powered assistant for software development—to generate test cases and identify runtime issues during the transition.

The team integrated these processes into a continuous integration and delivery pipeline, packaging applications into Linux containers and deploying them on Amazon Elastic Container Service (Amazon ECS), a fully managed service to build, manage, and run containerized applications. This method reduced manual steps, helped maintain code quality throughout the modernization process, and removed dependencies on Windows-based infrastructure.

By using AWS to migrate and modernize its .NET applications with AI-driven tools, Nol Universe accelerated development timelines, minimized operational overhead, and established a repeatable approach for modernizing additional applications across its environment.

Nol Universe completed the modernization of more than 1.5 million lines of code across about 1,500 source files in 6 weeks, with core transformation completed in 10 hours. Testing and error resolution, which previously required weeks of manual effort, were completed in days.

The company improved productivity for development teams by approximately three times and slashed development effort by about 50 percent. This made it possible for teams to shift focus from manual tasks to improving applications.

With a modernized, cloud-based architecture, the company can scale more efficiently, introduce new features faster, and lessen the burden of maintaining legacy systems. Building on this work, Nol Universe will continue its modernization goals across the company. “Using AWS, we established a reusable and scalable modernization plan, and we aim to systematically modernize other legacy systems to complete our digital transformation,” says YoonSeong.