The Atacama Large Millimetre/submillimetre Array (ALMA), the world's most powerful radio facility, is embarking on its most ambitious upgrade since its conception: the Wideband Sensitivity Upgrade (WSU). The WSU consists of an increase of the instantaneous spectral bandwidth by up to a factor of four, while retaining full spectral resolution over the full bandwidth. In addition, an upgrade of the full signal chain will translate in increases in sensitivity. In this talk, I will discuss the major scientific discoveries made with ALMA during the 10+ years of operations, I will present the WSU and its challenges and will conclude with the science that will be enabled once the WSU is delivered.