What does it mean to be truly successful? In the latest episode of our series in which Y TREE speaks to the people we admire about what success means to them, Harriet Johnston is joined by Niall Mills, the Managing Partner of Igneo Infrastructure Partners, for a conversation that seeks to get to the heart of this age-old question. Drawing on Niall’s upbringing, his early passion for getting to the bottom of how things worked, and his career to date, Harriet and Niall delve into questions around meaning and fulfillment, the power of mentorship and ‘paying it forward’, and the importance of sustainability in any definition of success, both professionally and personally.