Explore the groundbreaking integration of LAMBDA functions into Excel in this 19-minute conference talk from Lambda Days 2023. Discover how a multi-year collaboration between product and research teams has transformed Excel into a Turing-complete programming language, bringing pure functional programming to spreadsheets. Learn about the challenges faced during this journey and witness demonstrations of the powerful new capabilities now available in Excel, powered by functional programming principles. Gain insights into exciting ongoing research ideas being explored in collaboration with the Excel team. Understand how this development has revolutionized the world's most widely used programming language, opening up new possibilities for spreadsheet users and programmers alike.