Particle colliders have played and continue to play a central role in the exploration of the most fundamental building blocks of nature. Lepton colliders provide unique opportunities for precision measurements that may pave the way to the discovery of new phenomena. The Belle II experiment at SuperKEKB is one of the key facilities currently in operation, poised to acquire a significant dataset over the coming years. I will discuss examples of the physics program and of the detector technologies used to deliver it, discuss key challenges and will give also a broader perspective on lepton collider physics and detector technology.