This dissertation examines the social history of development in the late colonial and early post-colonial era through the lens of family history. Focusing on the everyday lives of middle-ranking Zionist Jewish employees of Solel Boneh, a major Israeli construction company, the study argues that kinship relationships, household economics, and family strategies were crucial for capitalizing on opportunities and achieving upward mobility in the developing world. It thus addresses scholarly neglect of family in understanding international development and sociologizes and historicizes the concept of the "development expert." The research highlights the transnational nature of class formation and the interconnectivity of nation-building projects in the transition from empire to nation-state. It argues that the political and economic history of Zionism cannot be confined to events within historical Palestine. Solel Boneh's extensive work across multiple countries underscores the transnational nature and global contexts of Zionist and Israeli development. Adopting a microhistorical approach, the study provides insight into the daily lives and professional trajectories of individuals involved in the development encounter, shedding light on the social makeup and shifting status groups within the international developer class. In sum, this dissertation contributes to global social history by offering a nuanced understanding of family and kinship networks in the history of development, and highlights interconnected local, national, and global processes to understand Zionism in development.