During the last decades, strong gravitational lensing has become a powerful tool that can be used to study astronomical objects with different physical scales. It has also proven to be a promising diagnostic that can help solve some of the most important problems in cosmology. We have now reached a critical time for strong gravitational lensing research, as forthcoming large-scale surveys (Euclid, the Roman Space Telescope, the Chinese Space Station Telescope and the Vera Rubin Observatory) will map the entire sky and increase the number of known gravitational lenses from a few hundred to about 100 000. At the same time, strong gravitational lenses with current and forthcoming instruments (e.g. ALMA, JWST, E-ELT, SKA-VLBI) will spatially resolve scales that are beyond the reach of telescopes for individual objects in the high-redshift Universe. These new data will revolutionise our understanding of dark matter and structure formation, and offer unprecedented cosmological applications. This strong gravitational lensing symposium will bring together observational and theoretical members of the community to review their preparedness for this new era, to discuss advanced statistical techniques and possible systematics limitations, and to foster novel collaborations.