In this course we introduce today’s most important IT concepts and technologies that are needed to realize e-Governance and e-Government services, systems and system landscapes. We delve into the typical multi-tiered architecture of today’s enterprise applications. We look at databases and database programming, enterprise application servers and web programming. We discuss IT system landscapes and IT system interoperability. In order to do so, we start by explaining basic concepts of network computing along the lines of the OSI layer model. We proceed with explaining the well-established service-oriented architecture as well as microservices architecture, cloud computing technologies and DevOps technologies. Eventually, we discuss the design, realization and operation of data exchange layers. We do so by investigating the Estonian XROADs solution. The course heavily relies on a combination of learning styles, i.e., presentations, collaborative learning sessions and practical experimentations.