10 — Monitor & Observe

Data Quality Gates#

Data✓ Mathematical
◆ The PatternAutomated checks that stop bad data before it reaches your model

Garbage in, garbage out — but in production, garbage arrives silently. Data quality gates enforce schema validation, range checks, freshness constraints, and completeness thresholds. They sit in your pipeline before feature engineering and before inference.

// Interactive — data quality pipeline flow
# Python — Great Expectations data quality check
import great_expectations as gx

context = gx.get_context()
ds = context.sources.add_pandas("prod_data")
asset = ds.add_dataframe_asset("batch", dataframe=df)

expectations = [
    gx.expectations.ExpectColumnValuesToNotBeNull(column="user_id"),
    gx.expectations.ExpectColumnValuesToBeBetween(
        column="price", min_value=0, max_value=100000),
]
Pattern bridge: Data quality gates are the production equivalent of missing data strategies — catching the problem before it corrupts your analysis. In markets, data hygiene (adjusting for splits, dividends, survivorship) serves the same protective role.
← Previous
Shadow Mode & Champion/Challenger
Open in the full reader, with the topic sidebar →