This report addresses the critical need to update and refactor legacy software within ATM (Air Traffic Management). Legacy systems can be integral to many businesses and have a risk of suffering from high technical costs and inefficiencies due to outdated technologies. This project focuses on a legacy ATM system owned by Combitech. The primary objective is to merge two separate components, developed in Java and C#, to reduce technical debt and prepare for an anticipated endpoint API update. By employing the Adapter design pattern, the report also aims to ensure the system’s adaptability to the future endpoint API update. The results demonstrate a significant reduction in technical debt, improved code maintainability, and enhanced overall system reliability. The results also show a way of guiding the developers in implementing necessary functionality into the adapter when the endpoint API update arrives. This study highlights the importance of proactive system refactoring to maintain operational efficiency and adaptability in evolving technological landscapes.