The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based facility for very-high-energy gamma-ray astronomy, designed to explore the non-thermal Universe with unprecedented sensitivity. The Large-Sized Telescopes (LSTs) play a key role in CTAO by extending its sensitivity down to the lowest energies, while atmospheric monitoring systems such as LIDARs are essential for the accurate calibration of Cherenkov data. IFAE is deeply involved in the development, commissioning and operation of the LSTs as well as the LIDAR. The student will have the opportunity to participate in the commissioning and testing of either the LST cameras or the LIDAR system, contributing to hardware tests, performance validation, and data analysis.