By strongly coupling a neutral atom array with an optical cavity, we achieve improved control over measurements and interactions within the neutral atom platform. The cavity photons serve two roles: they efficiently transfer quantum information from the atomic ensemble to external measurement devices, and they act as force carriers, facilitating long-range interactions among the atoms. By selectively coupling a single atom to the cavity mode, we achieve rapid mid-circuit measurements without perturbing the quantum coherence of the other atoms—a crucial step toward quantum error correction. Conversely, the collective emission from multiple atoms into the cavity can be coherently enhanced or suppressed. We demonstrate atom-by-atom control over collective light-atom interactions, observing both super- and sub-radiant cavity emissions from the constructed atomic ensembles. This collective atom-cavity coupling sets the stage for engineering long-range interactions through photon exchange, enabling the observation of self-organization phase transitions in mesoscopic systems and revealing key hallmarks of mesoscopic physics. Finally, I will briefly outline my future research plans to develop quantum systems that are robust against noise and decoherence using atoms and light.