 This paper provides an extensive review of the current state of the art of the wind farm design and optimization, WFDO, problem. It covers the various models used to describe the performance of wind farms, as well as the numerical approaches used to optimize them. Additionally, it discusses the potential applications of these techniques to real-world wind farms. Finally, it proposes a comprehensive agenda for future research. This article was authored by Jose F. Herbert Acero, Oliver Probst, Pierre-Ellouin Rithour, and others.