“…This role is usually referred to as first-stage retrieval or candidate generation. Multi-stage ranking architectures have been studied extensively by academic researchers [Matveeva et al, 2006, Cambazoglu et al, 2010, Wang et al, 2011, Tonellotto et al, 2013, Asadi and Lin, 2013, Capannini et al, 2016, Clarke et al, 2016, Chen et al, 2017, Mackenzie et al, 2018 and there is substantial documentation that many commercial applications are designed in this manner [Pedersen, 2010, Liu et al, 2017, Huang et al, 2020, Zou et al, 2021.…”