Versioned Late Materialization for Ultra-Long Sequence Training in Recommendation Systems at Scale. - Liang Guo; Ge Song; Litao Deng; Jianhui Sun; Chufeng Hu; Lu Zhang; Zhen Ma; Shouwei Chen; Weiran Liu; Sarang Masti Sreeshylan; Xiaoxuan Meng (CoRR, 2026)