As more and more startup companies are founded every year worldwide, building up one’s own business does not get easier. Since 9 out of 10 startups fail, future entrepreneurs are well advised to take a look at potential reasons for failure and success. Learning from others’ mistakes and studying success stories can improve their own performance and help to avoid critical errors. The academic paper at hand will provide valuable insights for entrepreneurs. It not only states the most important terms concerning startups but also lists the most important factors for a startup company’s success, according to literature review. Delineating both internal and external factors, this thesis not only delivers a synoptic view of potential challenges inside a startup as well as in its ecosystem, but also juxtaposes these influences in opposition. The second part of this paper analyzes a series of interviews with twelve startup founders from three different regions (the province of North-Rhine Westphalia in Germany, Budapest in Hungary and the state of California in the US). Their views and experiences will be summarized and put into the context of their respective startup ecosystem.