This conference is a celebration of the mathematical career of Szymon Dolecki, representing advances in the various fields he contributed to: Control Theory and observability (main speaker: Enrique Zuazua), Optimization (main speaker: Jean Paul Penot), Topology (main speakers: Alexander V. Arhangel’skii, Ahmed Bouziad, Jean Goubault-Larrecq, Steve Watson), as often as possible from the point of view of the unifying theme of convergence space theory (workshop leader: Frédéric Mynard), a domain of which he is one of the most prominent world specialist and that centrally occupied the later part of his career.