Training-serving skew
Training-serving skew is a mismatch between the data, feature representations, or computations used during model training and those used to generate predictions.
Machine Learning System Design
A condition in which a machine learning model performs poorly because its training data does not represent the data encountered during application or serving.
- How it is used
- Frames production reliability as a data-representation problem requiring alignment between training inputs and application inputs.
- How deep it goes
- Explains causes, gives environmental and image examples, and recommends retraining or adaptation, without detailing implementation mechanics.
- Examples
- Uses crowdsourced versus real-world images, laboratory versus poor-lighting photos, and a St. Petersburg–Cyprus deployment mismatch.
- What you can do after
- Diagnose/debug with it by comparing production inputs with training data and responding through broader collection, labeling, retraining, or adaptation.
Read how Machine Learning System Design explains training-serving skew →
Machine Learning Platform Engineering
Training-serving skew is a discrepancy between the feature transformations or data seen during model training and those applied during inference.
- How it is used
- Prevents inconsistent features from entering training and inference workflows in production ML systems.
- How deep it goes
- Defines the discrepancy, identifies differing transformations as a cause, and stops short of detailed detection or remediation procedures.
- Examples
- Illustrates skew through different transformations during training and inference, including complex joins across multiple data sources.
- What you can do after
- Apply it via feature stores that serve transformed features through offline and online paths.
Read how Machine Learning Platform Engineering explains training-serving skew →
Related concepts
- feature storeaddressed by · A feature store is a system for managing and serving machine-learning features for use in model training and inference.
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