The case is devoted to the transition of the telecommunications company Tele2 to a management system based on the principles of continuous improvement of customer experience, or CX-transformation. The case describes the development of Tele2 in the Russian cellular market in 2003–2020. Firstly, it outlines the main aspects of the Tele2’s business strategy in 2003–2016. Secondly, it provides a detailed description of events that took place in 2015–2016, when Tele2’s financial and operational performance indicators dwindled, and the mobile operator was challenged to develop a new business strategy that meets the changing market realities. Finally, there is a description of a new customer-focused strategy that implied the integration of customer metrics into all organizational processes and the restructuring of the internal customer experience management system. The case describes actions taken by the company during 2017–2020 to implement customer experience management practices and outlines the key results of Tele2’s CX transformation. The case is based on Tele2’s internal reports, retrospective interviews with the company’s representatives involved in the CX transformation process, and secondary opensource information. The case can be used to discuss the prerequisites, goals, components, and success factors of CX transformation.