Data Scientist · Phone Screen · Technical Discussion

American Express — Data Scientist ✅ Passed

Level: Junior-Level

Round: Phone Screen · Type: Technical Discussion · Difficulty: 3/10 · Duration: 120 min · Interviewer: Neutral

Topics: Machine Learning, Statistics, Bias-Variance Tradeoff, Logistic Regression, ROC, AUC, Lasso Regression, Ridge Regression, Type I Error, Type II Error, Model Metrics

Location: New York, NY, US

Interview date: 2022-02-15

Summary

I had two rounds of technical phone screens that focused on machine learning concepts. The rounds were similar and covered various ML terms and model evaluation metrics.

Details

I applied for a Global Decision Data Scientist position in NYC after seeing it on my school's mailing list. About a month later, HR contacted me to schedule two rounds of technical phone screens. The email indicated one round would focus on ML and the other on stats, but both rounds covered similar ML concepts.

Round 1:

• I was asked to explain the following terms:
  • Bias-variance tradeoff
  • Logistic Regression
  • ROC
    • Follow-up: When is AUC unreliable, and what should be done?
  • Lasso & Ridge
    • Follow-up: How are these used in deep learning?

Round 2:

• I was asked about some basic concepts, including:
  • Bias-variance
  • Type I and Type II errors
• I was asked what metrics can be used to measure a model.
• I was asked detailed questions about several projects on my resume.