codebase-comprehension-algorithms

Mapping an unfamiliar codebase into feature/business domains — answering "what is this about", "which files implement feature X", "where is the architectural spine", or reviewing a refactor that crosses module boundaries. 47 algorithms across 9 categories — graph construction (omnipresent filter, multilayer, SCC), lexical preprocessing (Samurai, TF-IDF), community detection (Leiden, Infomap, SBM, MCL, Walktrap, spectral, HDBSCAN), architecture recovery (Bunch+MQ, ACDC, Limbo, Reflexion, DSM), topic modelling (LDA, LSI, NMF, HDP), evolutionary coupling (Gall, ROSE), information-theoretic (NCD, MI, MDL, naturalness), centrality (PageRank, HITS, betweenness, TextRank), validation (MoJoFM, ARI/NMI, resolution limit, consensus, co-change prediction, ablation). Trigger without explicit "clustering" mention — codebase grokking, dependency mapping, domain extraction, architecture-recovery validation all apply.