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PROFESSIONAL-MACHINE-LEARNING-ENGINEER · Question #148

You deployed an ML model into production a year ago. Every month, you collect all raw requests that were sent to your model prediction service during the previous month. You send a subset of these req

The correct answer is D. Run training-serving skew detection batch jobs every few days to compare the aggregate. Training-serving skew detection compares the statistical distribution of incoming production requests against the training data distribution. When these distributions diverge significantly, it is a strong proxy signal that model performance is degrading - without requiring expens

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

Question

You deployed an ML model into production a year ago. Every month, you collect all raw requests that were sent to your model prediction service during the previous month. You send a subset of these requests to a human labeling service to evaluate your model's performance. After a year, you notice that your model's performance sometimes degrades significantly after a month, while other times it takes several months to notice any decrease in performance. The labeling service is costly, but you also need to avoid large performance degradations. You want to determine how often you should retrain your model to maintain a high level of performance while minimizing cost. What should you do?

Options

  • ATrain an anomaly detection model on the training dataset, and run all incoming requests through
  • BIdentify temporal patterns in your model's performance over the previous year. Based on these
  • CCompare the cost of the labeling service with the lost revenue due to model performance
  • DRun training-serving skew detection batch jobs every few days to compare the aggregate

How the community answered

(33 responses)
  • A
    15% (5)
  • B
    6% (2)
  • C
    9% (3)
  • D
    70% (23)

Explanation

Training-serving skew detection compares the statistical distribution of incoming production requests against the training data distribution. When these distributions diverge significantly, it is a strong proxy signal that model performance is degrading - without requiring expensive human labeling for every batch. Running this every few days provides timely detection while minimizing labeling costs. Option A (anomaly detection on all requests) doesn't directly indicate when to retrain. Option B (temporal patterns) is less precise and actionable. Option C (cost vs. revenue comparison) is a business analysis, not a monitoring strategy that triggers retraining.

Topics

#Model drift#Training-serving skew#ML monitoring#Retraining strategy

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