Many firms are unable to achieve the productivity benefits that digital technologies offer as their information technology (IT) infrastructures are highly inflexible, often cobbled together through a series of unrelated IT projects with little attempt made at systems integration. Increasingly, firms have been developing a digital core that integrates processes, data and technical infrastructure to take advantage of digital technologies. A digital core allows firms to exploit the capabilities of digital technologies through providing the infrastructure needed to support these technologies and ensure they are effectively integrated. This chapter highlights common causes of poor IT performance and outlines the concept of the digital core. It considers the role of digital maturity frameworks and the importance of modular architectures in the transition to building a digital core. The chapter highlights the key practices required for building a digital core including process improvement, organisational redesign, sourcing strategy, customer experience and operational efficiency pathway choice and cybersecurity and resilience management.