Night lighting is a feature of modern society, particularly in highly urbanized and densely populated areas. Recent scientific literature has demonstrated the robust predictive capacity of light intensity as an indicator of economic development levels. This approach is especially valuable in contexts where official statistical data is unavailable. Accordingly, the purpose of this study is to leverage nighttime light data, captured via satellite from space, as a predictor of development trajectories in Mayotte since its transition to departmental status. The protracted institutional process that culminated in 2011 succeeded in initiating public transfer mechanisms. However, it sidelined debates on establishing a comprehensive economic development strategy for the territory. Presently, Mayotte, experiencing record-breaking demographic growth, remains significantly underdeveloped compared to other French regions. In this context, assessing the evolution of Mayotte’s development level is of paramount importance. By combining population data with emitted light intensity, this study constructs Lorenz curves and calculates Gini indices to analyze inequality trends. The findings suggest a marked deterioration in the living standards of individuals situated at the lower end of the income distribution, a group likely composed predominantly of illegal immigrants excluded from social welfare programs. Mayotte’s geographical proximity to the Comorian island of Anjouan exacerbates this challenge, as the departmental framework has not yielded the anticipated developmental outcomes. The inability of Lorenz dominance criteria to definitively assess improvements in welfare must be understood within this complex socio-economic reality. Today, managing the demographic pressure driven by immigration represents one of the most pressing challenges for Mayotte. It is unquestionably a prerequisite for achieving inclusive development.