My dissertation seeks to address the role of university-educated scientists and engineers (S&Es) during industrialization, with a particular focus on the sorting of S&Es into invention activities and their allocation process both within and across firms. To achieve this, I delve deeply into the historical context of Japan's industrialization from the late 19th to the early 20th century, a period marked by the simultaneous emergence of multiple heavy manufacturing industries, a higher education system in science and engineering, and the rise of extensively diversified conglomerates known as zaibatsu. Using a manually constructed individual career database encompassing nearly all Japanese university graduates in science and engineering from the cohorts of 1877 to 1920 as an empirical basis, I conduct three independent yet interconnected studies in this dissertation. In Chapter 1, I investigate the factors influencing the sorting of university-educated scientists and engineers (S&Es) into inventors by matching them with archival patent records. I find a strong positive correlation between academic excellence and the likelihood of becoming an inventor as well as invention productivity. These highly skilled individuals significantly contributed to inventions in fields associated with emerging heavy manufacturing industries. I also underscore a strong complementarity between their academic skills and post-graduation job experience, which synergistically facilitated the generation of inventions. In Chapter 2, I delve deeply into the (re-)allocation process of educated plant managers and engineers across establishments within a leading cotton-spinning firm, in conjunction with investment in physical capital. Through detailed analysis of plant-level data on human capital appointments, transfers, and capital investments, I illuminate the endogenous process of internal human capital (re-)allocations in alignment with evolving strategic priorities. Notably, the shift from cost leadership to product differentiation, driven by high-end spinning machines, engendered a three-way complementarity between managerial human capital, engineering human capital, and advanced technologies. In Chapter 3, I examine how S&E university graduates are allocated both externally (moves across different independent firms) and internally (moves across affiliated firms within diversified firms or conglomerates) and their implication for innovation. I demonstrate that internal mobility enhances individual invention performance, whereas external mobility diminishes it. However, these performance differences are primarily attributed to the selection of different quality of human capital. Additional analysis suggests that high-quality human capital tends to enter growing industries through internal mobility and be often placed in managerial positions that grant them to access complementary resources. Overall, my dissertation studies contribute to the literature on strategic human capital, corporate strategy, and economic emergence. I assert that the insights derived from the unique historical context of Japan’s industrialization can not only be applied to current emerging economies but also to new industries in developed countries wherein the supply of specialized talent is scarce and mega firms play a pivotal role in driving innovation.