The management of rotator cuff-deficient shoulders has developed significantly over time. Before the introduction of reverse total shoulder arthroplasty, treatment options for massive cuff tears, cuff tear arthropathy and complex proximal humeral fractures were restricted and could lead to poor outcomes. The reverse shoulder arthroplasty, successfully introduced by Grammont and colleagues, leveraged design features such as medialization and inferiorization of the glenohumeral centre of rotation, creation of a fixed fulcrum and recruitment of the deltoid as the primary motor of the arm, and revolutionized the treatment of these complex shoulder problems. With indications expanding, however, issues and complications such as scapular notching, instability and acromial stress fractures were observed, leading to further iterative development of design and technique. Modern developments include relative lateralization along with deltoid wrapping to enhance stability, range of motion, and implant life. This review explores the early concepts of reverse shoulder arthroplasty, outlines key biomechanical concepts, and discusses modern developments in surgical technique and strategies to mitigate complications while optimizing functional outcomes.