ALANeX is an inter- and transdisciplinary project that integrates benefits of LED technology and practitioner's experiences to develop future lighting transformation pathways and guide-lines for LED outdoor lighting systems based on sound scientific evidence. To do so, we bring together light engineers, practitioners, ecological and social sciences. While light engi-neers will ensure state-of-the-art knowledge and skills in the context of lighting technology, practitioners will contribute experience and needs of the broad public. Ecological and social scientists will provide comprehensive assessments of impacts of artificial light at night exper-imentally on various aspects of ecological systems at various hierarchical levels as well as on human health and perception based on state-of-the-art outdoor LED lighting. Stakeholder workshops will bring together scientists and practitioners to sketch transformation pathways for sustainable light at night in a concerted action.