This chapter systematically explores the venture builder phenomenon, differentiating it from startup studios, accelerators, and incubators. The global diffusion of venture builders is also traced, and their role as efficiency-driven, risk-mitigated alternatives to traditional startup support is examined. Drawing on empirical research and case studies across Europe, it identifies venture builders as organizations that actively co-create startups, offering capital, operational infrastructure, and strategic guidance. Seven defining features of venture building models are discussed: focus, idea sourcing, service package, volume, funding, governance, and output. The chapter highlights two major venture builder archetype groups emerging from the literature, founder-based and digital, and summarizes the key characteristics of their subtypes. It highlights how different configurations impact the scalability of ventures, offering early insights into which features may be more conducive to scaleup creation. This chapter serves as a cornerstone for understanding the structural DNA of venture builders.