We study the effects of crucible experiences along multiple sensitive periods on career progression. While prior literature has hinted that individuals can be imprinted during multiple sensitive periods, not just during the early career, there has been scant attention to it theoretically and empirically. We use unique administrative data of 8662 U.S. Army officers who graduated from the United States Military Academy (USMA) at West Point from 1995 to 2004 and exploit a natural experiment to estimate robust treatment effects. In our setting, workers were quasi-randomly assigned to crucible locations such as war zones in Iraq and Afghanistan and, importantly for our study, the quasi-random assignment to crucibles could be during the early career of the individual (i.e., during the first five years of the career), mid-career (between the fifth and ninth year of the career), or both during the early- and mid-career. We exploit this allocation protocol to estimate robust treatment effects of crucible exposure on an objective measure of career advancement—promotion to the rank of major. We additionally exploit variation in whether the repeated crucible assignments are in the same or different geographic/cultural contexts to study whether crucible assignment triggers one of two possible human capital development and learning mechanisms: building absorptive capacity in a relatively narrow context or exaptation and developing dynamic capabilities. Our evidence suggests that based on task characteristics, the former mechanism is in play in our empirical context. Our results contribute to literatures on imprinting, development of managerial cognitive capabilities, learning and career experiences, and how the geographic/cultural context can shape human capital.