In this volume of work, I aim to explore how young firms build knowledge to gain sustainable competitive advantage. Such a research objective requires me to pay attention to both knowledge as content and the process of knowing (Polanyi, 1966). Furthermore, it also requires me to unpack the 'black box' issues by examining individual action as well as the way interaction among individuals leads to organizational outcomes (Gephart, 2004). Hence, I adopt a real-time longitudinal multiple case-design in this study. Data were collected at multiple levels over a period of 38 months from Oct 2003 to Dec 2006 on 12 high-tech start-ups in the UK. Drawing upon this unique dataset, I examine the-knowledge building process at both micro- and macro-level. At micro-level (Chapter 3), building upon the brokering literature (Simmel, 1950; Burt, 1992; Pollock et aI., 2004), I explore the issue of how a firm could utilize different types of broker in its network construction process in;order to adapt to the changing knowledge needed as it grows. I classify two types of broker with respect to a firm's evolutionary stages. Architects help to build a firm's network by bridging structural holes across different stages of the organization life-cycle, whilst functionalists help to bridge structural holes at a single development stage. Drawing upon 229 brokering incidents by 115 brokers involving 12 UK high-tech start-ups, I show that architects and functionalists not only co-exist, but also interact with each other as a firm grows. They have complementary roles. Moreover, my data reveals that brokers may not always act according to type. This chapter contributes to a dynamic view of knowledge brokerage. At macro-level (Chapter 4), drawing upon the search literature (CXert and March, 1963; Nelson and Winter, 1982; Gavetti and Levinthal, 2000), I aim to explore the origin and dynamics of strategic search. In particular, I investigate how the patterns of interaction between cognition and action differ in a guided vs. an experiential search proce·ss. I adopt a semi-grounded approach (Isabella, 1990) to examine the search processes of the 12 high-tech start-ups from the. pre-founding stage. I illustrate how the pattern of interaction differs. Moreover, my data suggests that different search processes starting·?from a similar stage may reach a similar end stage through different knowledge building paths. This·seems to indicate a false sense of 'knowledge sameness'. The chapter contributes to the, search literature and also informs the modelling community. Putting the above together, the findings of this study portray the nature of knowledge as complex, nested and multi-dimensional, as well as supporting a process view of knowledge. Moreover, the findings not only highlight the critical role of strategy making in a young firm's survival and its subsequent quality of life (Hitt et aI., 2001), but also enhance our understanding of the origin and evolution of a firm's .strategy. To sum up, this study illustrates the importance of vIewmg different theoretical lenses and methods as complementary rather than competing. Furthermore, this study attempts to bridge the methodological gap between micro- and macro-level analysis without dismissing 'the very notion of levels' (Brown and Duguid, 2001). Therefore, I argue that this study contributes to a dynamic and holistic view of knowledge management in the firm (Nonaka and Takeuchi, 1995; Spender and Grant, 1996).