Abstract. Uniform empirical comparison of six classifiers (LR, DT, RF, GB, XGB, MLP) on a 296,457-instance dataset assembled from five mature open-source systems (Elasticsearch, Spring Boot, Hadoop, Kafka, Express). Stratified 5-fold cross-validation with paired-t and Wilcoxon significance testing. Random Forest is best (AUC 0.8998, F1 binary 0.6355, F1 macro 0.7595); XGBoost is the closest competitor (AUC 0.8955).
Contributions. Multi-model Gini feature importance with explicit caveat on Strobl 2007 high-cardinality bias; documentation of the deployed model gb-paper1-v4-fixed_age; honest threats-to-validity disclosure including the file_age_days sign bug that contaminated 40% of rows in the prior revision and is now eliminated.