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PROFESSIONAL-MACHINE-LEARNING-ENGINEER · Question #63

You built and manage a production system that is responsible for predicting sales numbers. Model accuracy is crucial, because the production model is required to keep up with market changes. Since…

The correct answer is B. Lack of model retraining. This is a classic example of model staleness caused by data drift or concept drift. The model was trained on historical data that reflected past market conditions. Over time, market dynamics change - consumer behavior, pricing patterns, seasonal trends, and economic conditions…

Submitted by tom_us· Apr 18, 2026Monitoring, optimizing, and maintaining ML solutions

Question

You built and manage a production system that is responsible for predicting sales numbers. Model accuracy is crucial, because the production model is required to keep up with market changes. Since being deployed to production, the model hasn't changed; however the accuracy of the model has steadily deteriorated. What issue is most likely causing the steady decline in model accuracy?

Options

  • APoor data quality
  • BLack of model retraining
  • CToo few layers in the model for capturing information
  • DIncorrect data split ratio during model training, evaluation, validation, and test

How the community answered

(42 responses)
  • A
    10% (4)
  • B
    86% (36)
  • C
    2% (1)
  • D
    2% (1)

Explanation

This is a classic example of model staleness caused by data drift or concept drift. The model was trained on historical data that reflected past market conditions. Over time, market dynamics change - consumer behavior, pricing patterns, seasonal trends, and economic conditions all evolve - causing the real-world data distribution to diverge from what the model learned during training. Since the model itself has not been updated, its predictions become progressively less accurate. The solution is to regularly retrain the model on fresh data to keep it aligned with current market conditions. Poor data quality (A) would typically cause immediate issues rather than a steady decline. Architectural issues (C) or train/test split issues (D) would have been apparent at initial deployment, not as a gradual decline post-deployment.

Topics

#Model drift#Model retraining#Model maintenance#Production ML

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