#data quality

7 data quality interview questions, asked at Cohere, Databricks, Mercor and 5 more companies. Last asked Sep 2026.

Review a feature pipeline pull request, then serve features by freshnessML designYou are shown a pull request that changes a feature pipeline: the code that turns raw events into model features. All its tests pass. Review it live and explain what could go…
Last asked Sep 2026
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Find noisy annotators and retrain a classifier without themCodingA classifier is trained on labels from several human annotators, and some of them label carelessly. Find which annotators are unreliable, drop their labels, retrain, and show…
Last asked Sep 2026
Load daily LLM chat logs into a warehouse idempotentlySystem designEvery day one JSONL file of LLM conversations lands in object storage; each line is a conversation with an id, a user id, its messages and metadata. Design the job that loads it…
Last asked Sep 2026
How data collection shapes model performanceML designPick a project from your resume and explain how its data was collected and processed. Then discuss how data choices (coverage, label quality, noise, imbalance, distribution shift)…
Last asked Sep 2026
Evaluate noisy data for LLM post-trainingML designYou have data collected for post-training a language model and some of it is noisy. How would you measure its quality, find the bad examples, and decide what to keep, fix or drop…
Last asked May 2026
Design quality checks for spreadsheet data used to train an LLMML designYou are building training or evaluation data from spreadsheets for a language model. Design the checks that catch bad examples: structural problems, wrong or inconsistent values…
Last asked Mar 2026
Diagnose a data pipeline's quality and performance problemsBehavioralAsked in a hiring-manager conversation for a solutions architect role: how do you diagnose a data pipeline whose output has quality problems, or whose runs have become slow? Walk…
Last asked Jul 2025