We introduce a light induced sequence enabling λ-orthogonal star polymer formation via an arms-first approach, based on an α,ω-functional polymer carrying tetrazole and o-methyl benzaldehyde moieties, which upon irradiation can readily undergo cycloaddition with a trifunctional maleimide core. Depending on the wavelength, the telechelic strand can be attached to the core at either photo-reactive end.