BillionToOne builds molecular diagnostics that detect disease at the single-molecule level. Our prenatal test is the only non-invasive screen for both recessive conditions and aneuploidies from one blood draw. Our oncology platform finds 50%+ more cancer treatment options than standard testing. Over 1 million tests processed to date. Every line of code here has a patient on the other end of it.
Revenue grew from $0 to ~$300M in four years, guiding $415-430M for 2026. Publicly traded and GAAP profitable. You'll work alongside clinicians and computational biologists on genuinely hard problems: scaling genomic pipelines, building digital infrastructure for complex test results, and shipping systems where correctness isn't optional.
Hiring across software engineering:
- Senior Software Engineer, Digital Experiences (Oncology and Prenatal)
- Senior Software Engineer, Oncology
- Senior Software Engineer, Prenatal
- Senior AI Engineer
Stack: Python, Django, Postgres, React, TypeScript, AWS, Docker, Terraform, Kafka, CircleCI, Datadog. AI-assisted dev tools (Cursor, Copilot, Claude Code).
Benefits: Access to the latest AI tools and models with unlimited usage to help you do your best work, 100% paid medical on select plans, 16 weeks fully paid parental leave, 401(k) with 4% match, daily catered lunch, on-site gym. Forbes Best Startup Employers 2024 & 2025.