The three-volume set LNCS constitutes the refereed proceedings of the 10th International Joint Conference on Web and Big Data, APWeb-WAIM 2026, held in Da Nang, Vietnam, during September 7-9, 2026.The 108 regular research papers, 24 special track papers, 1 industry paper, and 9 demo papers presented in these proceedings were carefully reviewed and selected from 309 submissions. The papers are organized in the following topical sections:Part I: Advanced Architectures, Database...