The discovery of the Campylobacter jejuni N-linked glycosylation system combined with its functional expression in Escherichia coli marked the dawn of a new era in glycoengineering. The process, termed protein glycan coupling technology (PGCT), has, in particular, been applied to the development of glycoconjugate vaccines. In this review, we highlight recent technical developments in this area, including the first structural determination of the coupling enzyme PglB, the use of glycotags for optimal glycan attachment and the possible applications of other glycosylation systems and how these may improve and extend PGCT.