Active Galactic Nuclei (AGN) represent some of the most energetic phenomena in the Universe, playing a fundamental role in galaxy evolution through accretion and feedback processes. In the era of the LSST (Legacy Survey of Space and Time), conducted by the Vera C. Rubin Observatory, time-domain astronomy will enter a new regime, enabling the monitoring of billions of sources over a decade with unprecedented depth. In this context, AGNs, particularly the so-called “changing-look AGN” (CLAGN), will be identified and studied on a large scale, allowing us to investigate rapid transitions in accretion states, changes in emission lines, and variations in the continuum. I will discuss the opportunities and challenges associated with the detection, classification, and analysis of AGN in the LSST era, highlighting the role of advanced statistical techniques, machine learning, and synergy with complementary spectroscopic surveys such as DESI and SDSS. In addition, I will also discuss the growing field of computational astrophysics in Brazil, which is expanding to meet the demands of this new era.