This dissertation (abstract and executive summary) studies the impact of founders’ background on alliances and firm performance. First essay examines the role of founders’ prior employer (parent) in shaping the alliance network of firms founded by employees (spinouts). I find that the spinouts that differ from their parent, partner with firms that have direct/indirect parent ties. While spinouts that are similar find partners with no parent ties. Second essay examines the effect of heterogeneity in the founders’ backgrounds on the start-up’s alliance, innovation, and performance. I find that founders’ background has no impact on start-up’s performance; instead, it shapes the resources within the firm.