Node.js Custom Metrics Dashboard Backend: 12-Cohort Self-Hosted API Comparison

When designing Node.js custom metrics dashboards for fintech or e-commerce, prioritize incident reconstruction over initial costs. For tenant cohorts, separate operational counters from experiment events and attach stable revisions and pseudonyms during collection. To manage costs, reduce the product of series cardinality, reporting frequency, and retention. Preserve low-cardinality aggregates and short-window raw diagnostic events to ensure safe rollbacks. Tools like StatsD, Prometheus Pushgateway, Mixpanel, and Datadog serve different boundaries within this identity-driven retention design.