We are looking for a Senior Software/System Architect with a strong software engineering background to drive security-related architectural improvements in a large, mature on-premise healthcare product. The ideal candidate has experience with monolithic/legacy C++ systems and can translate security requirements into practical architecture decisions while assessing technical impact, dependencies, and risks. Location - Bulgaria, Poland (remote) B2B contract, full-time (160-178 hours/month) Hourly rate in dollars - 40-45 RESPONSIBILITIES Analyze security requirements from a software and system architecture perspective. Define how security requirements should be implemented within the existing product. Design solutions for security issues that require architecture changes. Evaluate technical impact, dependencies, and implementation risks. Determine whether requirements should be addressed at application or infrastructure level. Define secure approaches for areas such as file processing, database access, authentication, external integrations, and other trust boundaries. Guide developers during implementation. Review proposed technical solutions. Ensure that changes remain compatible with the existing legacy architecture. Collaborate with the IT Security Expert. Support technical prioritization and decision-making. REQUIREMENTS Strong software engineering and architecture background. Experience designing solutions for large monolithic applications. Experience working with legacy C++ systems is strongly preferred. Understanding of Qt-based desktop/on-premise applications is an advantage. Experience introducing architectural changes into mature systems without destabilizing existing functionality. Good understanding of low-level application concerns such as memory management and threading. Ability to determine whether a security requirement should be solved at application, architecture, or infrastructure/environment level. Experience with on-premise enterprise or healthcare products is an advantage. Ability to translate security requirements into practical architectural solutions.Selling PointsWe are looking for an experienced Software/System Architect to support the security improvement of a large on-premise healthcare product. The product is a mature monolithic application implemented in C++ with a Qt-based user interface. Some security requirements cannot be solved through isolated code changes and require architecture-level decisions. You will work closely with the client's architects, developers, and security specialists.