Debugging Model Performance Issues

Summary

A practical skill interviewers test directly — given a model performing poorly, can you systematically narrow down whether it's data, features, architecture, or training issues.

• 1Build a mental checklist: data quality, label quality, feature leakage, overfitting, underfitting.
• 2Practice narrating your debugging process out loud, not just the final fix.
• 3Review a real bug you hit in a project and be ready to tell that story in an interview.