The development of reliable and scalable control software is a key requirement for the Cherenkov Telescope Array Observatory, where distributed subsystems must operate coherently and support increasingly automated observing strategies. This paper presents the architecture and design of the Telescope Control System of the Small-Sized Telescopes of the observatory, addressing the need for modularity, deterministic behavior, and long-term maintainability. The proposed solution adopts a set of software managers implementing well-defined interfaces and state machines, enabling predictable control flows and consistent interaction with heterogeneous hardware. Modern software engineering practices were applied, including containerized services, automated deployment workflows, and a comprehensive simulation environment. These elements were evaluated through prototypes and pathfinder activities that allowed us to explore design alternatives, validate the behavior of individual components, and assess the scalability of the overall architecture. Results from these exploratory tests indicate that the interface-driven and modular design supports robust operation, facilitates integration, and reduces the effort required for system evolution. While full implementation is currently in progress, the findings confirm that the proposed architecture provides a solid foundation for the test readiness review phase (the phase preceding formal integration testing) and can be effectively extended to future facilities requiring flexible, maintainable, and resilient control software.
Conforti et al. (Thu,) studied this question.