This document profiles Oleg Koss, an engineer and MBA with 10 years of experience in telecommunications who is currently the CX team leader at Kyivstar, the leading mobile operator in Ukraine. It provides details on Kyivstar's market position and key metrics like its 26 million mobile customers and monthly churn of around 2%. The remainder of the document outlines Oleg's approach to fixing poor customer experiences, which involves preparation, forming a cross-functional team, introducing the problem, diverging and converging on insights and solutions, prototyping, piloting, and measuring key performance indicators.