The Search for Neutrinoless Double-Beta Decay with KamLAND-Zen 800

The KamLAND-Zen experiment has recently provided stringent constraints on the neutrinoless double-beta decay half-life in ¹³⁶Xe using a xenon-loaded liquid scintillator. I will present the analysis of a data set with an unprecedented exposure of 970 kg yr of ¹³⁶Xe. This new data provides valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and has required the use of novel background rejection techniques including machine learning.