#data-quality

Machine Learning Medium Theory

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What is data leakage in machine learning?

Data leakage happens when training uses information that would not be available at real prediction time.

• Inflates evaluation scores
• Common in preprocessing mistakes
• Think carefully about time and target leakage

#data-quality #ml #validation

What is data leakage in machine learning?

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ETL / Data Engineering Medium Theory

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What are data quality checks?

Data quality checks validate assumptions like null rates, uniqueness, schema shape, and accepted value ranges.

• Catch bad data early
• Automate checks in pipelines
• Alert instead of silently passing errors

#data-quality #etl #validation

What are data quality checks?

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ETL / Data Engineering Medium Theory

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What is late arriving data?

Late arriving data shows up after the expected processing window and can break simple incremental assumptions.

• Common in event systems
• Needs watermark or backfill strategy
• Affects correctness of incremental models

#data-quality #etl #streaming

What is late arriving data?

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