Senior Software Engineer, Pretraining Data (AI)

Location: Onsite in Palo Alto, California; must be able to work in person at the Palo Alto office.

Annual salary: $220,000–$357,000 USD. Actual level and base salary depend on job-related knowledge, skills, education, and experience.

Company

Cursor AI builds AI products and frontier-model infrastructure, including systems for large-scale model training.

What you will do

• Design, build, and scale distributed infrastructure that transforms raw web, code, multimodal, and acquired data into training-ready datasets.
• Own high-throughput pipelines, orchestration systems, and tooling with reliable, observable, reproducible processing and end-to-end data lineage.
• Build models and algorithms to classify, rank, deduplicate, filter, and clean training data, and evaluate the impact of data mixtures and quality thresholds.
• Build and optimize web crawling systems covering URL discovery, prioritization, scheduling, fetching, parsing, and content extraction.
• Lead complex initiatives across data platform, data quality, crawling, acquisition, and model training teams; make architectural decisions and mentor engineers.

Requirements

• 5+ years of professional software engineering experience building distributed systems and/or large-scale data infrastructure.
• Ability to architect and ship end-to-end systems with high ownership and debug complex systems independently.
• Strong understanding of large-scale distributed systems and reliable operation at frontier scale.
• Experience leading technical projects across teams and mentoring engineers.
• Ability to work alongside AI agents.

Nice to have

• Strong infrastructure or data platform background with exceptional depth in a relevant area.
• Experience progressing rapidly into staff-level ownership or relevant domain experience.
• Interest in how pretraining data shapes model quality and in building systems that feed frontier training runs.

Culture & Benefits

• Full-time onsite work with ownership and visibility over systems supporting frontier model training.
• Equity and comprehensive medical, vision, and dental coverage.
• Access to a 401(k) retirement plan, short- and long-term disability insurance, life insurance, discounts, and other perks.