🔧 One Bug Hit 11 Rows. Another Hit 36 Million.

I built a predictive maintenance model on 37,164,054 telemetry records from an iron ore mine. Six months of alarms from haul trucks and excavators. The goal was to predict "Don't Go" events, the ones that stop a machine mid-operation, hours before they happen.

Before any of that, I had to deal with four data quality problems.

Here is what makes...