The engineering behind the technology that powers Bitcoin, known as Blockchain, has gained attention as a potential software solution for various industrial applications. The capability of revolutionising digital transactions brought significant interest in this technology and evolved greatly in the past decade. However, the development of applications beyond cryptocurrency has not yet kept pace. In this chapter, we will examine the basic design principles of blockchain technology using Bitcoin’s architecture as a foundation and understand the rationale behind its design and the limitation of scalability.