In this article, the engineering career of Rai Bahadur Jagmal Raja Chauhan (1887-1974) is explored as a case study to gain insight into the colonial technology-entrepreneurship-engineering nexus in late colonial India. Histories of technology in British India have tended to focus on the work of colonial scientific knowledge and European engineering institutions. The role of Indian contractors, builders, and technical entrepreneurs has been comparatively little studied, however. Jagmal Raja Chauhan hails from the Mistri community of Kutch, which is traditionally involved in construction and engineering work. He was the one of the most prominent railway contractors and infrastructure builders of India despite his lack of formal education in the first half of the 20th century. He was also involved in many engineering feats such as railway bridges and the building of docks and industrial enterprises—a testament to the importance of indigenous skills in the realization of colonial public works. The article seeks to demonstrate that in addition to British knowledge and skills in engineering, the building of colonial infrastructure relied on local technical traditions, community networks, and entrepreneurial efforts. The study focuses on the colonial institutions and indigenous technical knowledge through the lens of the Chauhan's career. It also examines the negotiation of opportunities by Indian contractors in the colonial economy, their acquisition of technical authority, and their role in the transformation of Indian transportation and industrial infrastructure. The article locates Chauhan within the larger discussions around technology transfer, colonial modernity, and agency of Indian actors in the creation of modern engineering landscapes.