Plan How Raw Text Becomes LLM Training Data: Filtering, Dedup, Mixing, Evaluation

Quick Overview

An NVIDIA product manager interview question about curating data to train a large language model. It tests understanding of pipeline stages such as extraction, quality filtering, deduplication, decontamination and data mixing, and how to validate curation choices and balance quality against quantity at scale.

Plan How Raw Text Becomes LLM Training Data: Filtering, Dedup, Mixing, Evaluation

Company: NVIDIA

Role: Product Manager

Category: Machine Learning

Difficulty: medium

Interview Round: Other

Walk through how you would turn raw text into a curated training set for a large language model, from choosing sources to the data the training job finally reads. ```hint Judge filters by the model Every filtering or deduplication choice removes tokens. Think about how you would find out whether a given step made the trained model better, not just the data cleaner. ``` ### Clarifying Questions - Is this for pretraining a base model from scratch, or for fine-tuning data such as instruction or preference examples, where volumes and quality checks differ? - Am I curating data for a model my own team trains, or designing a curation product that NVIDIA's customers run on their own data? - What capabilities, languages and domains should the model have (general chat, code, a specific industry), and roughly what token budget does the training plan allow? - Are there licensing, privacy or regional restrictions on which sources can be used? ### What a Strong Answer Covers - The stages from sourcing to training-ready shards: extraction, language identification, quality filtering, deduplication, safety and personal-data handling, benchmark decontamination, and mixing. - How quality is defined and measured, including classifier-based filtering and the bias it can introduce. - How curation choices are validated with small proxy training runs and held-out evaluations. - Scale, cost and reproducibility: throughput on very large corpora, GPU acceleration, versioning and lineage. - The trade-off between quality and quantity, plus governance concerns such as licensing and opt-outs. ### Follow-up Questions - After aggressive filtering you have too few high-quality tokens for the planned training run. What are your options, and what does each cost? - A model trained on the new dataset scores higher on public benchmarks, but users say it got worse in a language you care about. How do you investigate? - If you were the PM for a GPU-accelerated curation library, which stage would you accelerate first, and how would you measure adoption?

Overview: An NVIDIA product manager interview question about curating data to train a large language model. It tests understanding of pipeline stages such as extraction, quality filtering, deduplication, decontamination and data mixing, and how to validate curation choices and balance quality against quantity at scale.

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NVIDIA
Jun 1, 2026
mediumProduct ManagerOtherMachine Learning
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Walk through how you would turn raw text into a curated training set for a large language model, from choosing sources to the data the training job finally reads.

Clarifying Questions Guidance

  • Is this for pretraining a base model from scratch, or for fine-tuning data such as instruction or preference examples, where volumes and quality checks differ?
  • Am I curating data for a model my own team trains, or designing a curation product that NVIDIA's customers run on their own data?
  • What capabilities, languages and domains should the model have (general chat, code, a specific industry), and roughly what token budget does the training plan allow?
  • Are there licensing, privacy or regional restrictions on which sources can be used?

What a Strong Answer Covers Guidance

  • The stages from sourcing to training-ready shards: extraction, language identification, quality filtering, deduplication, safety and personal-data handling, benchmark decontamination, and mixing.
  • How quality is defined and measured, including classifier-based filtering and the bias it can introduce.
  • How curation choices are validated with small proxy training runs and held-out evaluations.
  • Scale, cost and reproducibility: throughput on very large corpora, GPU acceleration, versioning and lineage.
  • The trade-off between quality and quantity, plus governance concerns such as licensing and opt-outs.

Follow-up Questions Guidance

  • After aggressive filtering you have too few high-quality tokens for the planned training run. What are your options, and what does each cost?
  • A model trained on the new dataset scores higher on public benchmarks, but users say it got worse in a language you care about. How do you investigate?
  • If you were the PM for a GPU-accelerated curation library, which stage would you accelerate first, and how would you measure adoption?