Research Engineer - Pretraining Data

Prime Intellect

San Francisco, CA

Remote

Who this role is best for

Geared toward data engineers comfortable with scalable data processing and collaboration with researchers, this role suits candidates with a background in open-source AI infrastructure and a preference for remote or hybrid work arrangements in the San Francisco area.

Best fit for

Candidates with experience in large-scale data curation and a passion for open-source AI infrastructure
— “the infrastructure frontier AI labs build internally, made available to every ambitious AI team”
Professionals with a background in data pipelines and distributed systems
— “Strong programming skills in Python and a record of building reliable data-processing or distributed systems”

Things to consider

This role requires handling data-quality issues and translating research goals into actionable experiments
— “Ability to diagnose data-quality issues and translate research goals into measurable checks and experiments”
The position involves preparing data for specialized model training, such as long-context learning and reasoning
— “Prepare and evaluate data for long-context learning, reasoning, and coding”

How to stand out

Emphasize your track record in building scalable data pipelines and handling large datasets
— “Experience working with large datasets and managing the practical tradeoffs of storage, compute, throughput, and reproducibility”
Highlight your ability to work on end-to-end data problems and collaborate with researchers
— “Comfort owning an evolving technical problem end to end and working closely with researchers”
Showcase your experience with data deduplication and quality scoring techniques
— “Deduplication, text classification, quality scoring, synthetic data, or training-data contamination analysis”
Demonstrate your knowledge of tokenization and training data loaders for large models
— “Familiarity with tokenization, training data loaders, and the needs of large model-training runs”

Pace · Fast PacedCollaboration · MediumAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

Building scalable pipelines for data processing
Improving data quality and coverage
Developing checks for data quality and contamination

Typical background

Experience in data engineeringBackground in machine learning or AI

Skills & requirements

Required

PythonData ProcessingLarge DatasetsDistributed SystemsData Quality ChecksData PipelinesWeb CrawlingCode-data CollectionDeduplicationText ClassificationSynthetic DataTraining-data Contamination Analysis

Preferred

Machine LearningNatural Language Processing

Stack & domain

Python

About the role

Original posting from Prime Intellect via Ashby

OWN YOUR INTELLIGENCE
Prime Intellect is building the open superintelligence stack: the infrastructure frontier AI labs build internally, made available to every ambitious AI team.
Our platform, Lab, unifies compute, environments, evaluations, secure sandboxes, high-performance training, and deployment into one full-stack system for post-training at frontier scale - from SFT and RL to tool use, agent workflows, and continuously improving production models. We are building open frontier AI: open-source models trained end to end for long-horizon tasks like autonomous research, and the full-stack platform our own research team uses to build them. The next generation of AI companies, enterprises, and research teams do not just need more GPUs. They need the ability to turn their own workflows, tools, data, and feedback loops into superintelligence they own.
Prime Intellect has raised $150M in total funding from Founders Fund, Radical Ventures, NVIDIA, and exceptional AI, infrastructure, and enterprise operators, including Andrej Karpathy, Dwarkesh Patel, and leaders and founders from Ramp, Perplexity, Harvey, Mercor, Zapier, Datadog, Cognition, OpenAI, Thinking Machines, Together AI, SemiAnalysis, LangChain, Browserbase, Cloudflare, Sierra, Databricks, Airbnb, OpenRouter, Standard Intelligence, Fleet, Core Auto, and more. We are looking for people who want to build at the intersection of frontier research, real infrastructure, and go-to-market for a category that does not fully exist yet.
ROLE IMPACT
Build the data behind Prime Intellect’s next generation of open models. You’ll find valuable sources, turn them into training-ready corpora, and work with researchers to test what actually improves the model. Your work will shape both broad pretraining and the data used to develop reasoning, coding, and long-context capabilities.
RESPONSIBILITIES
Find, evaluate, and collect valuable training data from web, code, and technical sources.
Build scalable pipelines that turn raw data into training-ready corpora through extraction, cleaning, deduplication, and filtering.
Develop checks for data quality, coverage, and contamination, and use them to improve collection and processing.
Work with researchers on data mixtures and sampling strategies for pretraining and midtraining.
Prepare and evaluate data for long-context learning, reasoning, and coding, testing synthetic data where it proves useful.
Run controlled data experiments and use model evaluations to decide which sources, mixtures, and processing choices are worth scaling.
Make large-scale data processing efficient, reproducible, and recoverable, with clear source provenance and dataset versioning.
REQUIREMENTS
Strong programming skills in Python and a record of building reliable data-processing or distributed systems.
Experience working with large datasets and managing the practical tradeoffs of storage, compute, throughput, and reproducibility.
Ability to diagnose data-quality issues and translate research goals into measurable checks and experiments.
Comfort owning an evolving technical problem end to end and working closely with researchers to test assumptions and improve the system.
Relevant experience may include:
Web crawling, document extraction, code-data collection, or large-scale corpus curation.
Deduplication, text classification, quality scoring, synthetic data, or training-data contamination analysis.
Data-mixture experiments, curriculum learning, or measuring how dataset changes affect model performance.
Nice to have
Experience preparing datasets for language-model pretraining, continued pretraining, or midtraining.
Work with distributed processing frameworks such as Spark, Ray, or comparable systems.
Experience with multilingual, mathematical, scientific, or repository-level code data.
Familiarity with tokenization, training data loaders, and the needs of large model-training runs.
Depth in data acquisition, scalable processing, or data research can be a strong starting point. We don’t expect every candidate to have worked across all of them.
BENEFITS AND PERKS
Cash Compensation Range of $150-350k, including equity incentives, aligning your success with the growth and impact of Prime Intellect.
Flexible work arrangements, with the option to work remotely or in-person at our offices in San Francisco.
Visa sponsorship and relocation assistance for international candidates.
Quarterly team off-sites, hackathons, conferences and learning opportunities.
Opportunity to work with a talented, hard-working and mission-driven team, united by a shared passion for leveraging technology to accelerate science and AI.
If you're excited about the opportunity to build the foundation for the future of decentralized AI and create a platform that empowers developers and researchers to push the boundaries of what's possible, we'd love to hear from you.

Source: Prime Intellect careers (Ashby)