This handbook outlines how the Build4Skills program integrates traineeships into infrastructure construction projects in Asia and the Pacific, backed by the Asian Development Bank (ADB). The aim is to offer affordable training that boosts employability and widens project scope. It serves as a practical, step-by-step guide complete with templates detailing trainee requirements. The handbook explains the process of integrating Build4Skills traineeships, coordinating with institutions and contractors, and delivering effective training. It also highlights the advantages of work-based training for contractors, the slight budget increases needed to integrate training into projects, and the potential for strategic collaboration to generate innovative solutions to global challenges.