Status and prospects of rare decays at ATLAS and CMS

Recent results from rare flavour decays searches achieved using proton-proton collision data at √s=13 TeV by ATLAS and CMS are presented. They include the studies of B⁰₍ₛ₎→μ⁺μ⁻ decays carried out by both experiments and the first observation of the η→4μ double Dalitz decay by CMS using Run 2 data. The trigger strategies allowing for rare decays searches involving soft muons in Run 3 are also discussed.