BillionToOne pushes the boundaries of molecular diagnostics through quantitative technologies. Our molecular counter platform is the only technology that can accurately count the DNA molecules at the single base-pair single-count level. This technology increases the resolution of cell-free DNA diagnostics by over 1000-fold and unlocks a wide range of prenatal and oncology applications. Our first product, UNITY, enables non-invasive detection of single gene disorders such as cystic fibrosis, sickle cell disease, spinal muscular atrophy, and thalassemias from a single blood tube taken from the pregnant mother. These are the most common genetic disorders in the world (with more than 100 million carriers), and their prenatal detection currently requires invasive methods with high miscarriage risk. UNITY has achieved 100% accuracy in clinical trials and is going to be available in May.BillionToOne has raised funding from global, prominent institutional funds such as Hummingbird Ventures, NeoTribe Ventures, and Y Combinator, as well as from prominent angel investors who previously invested in SpaceX, Box, and Palantir.


United States

Staff Software Engineer

Do you want to work with the cutting edge of medical diagnostics, saving millions of lives, while working with some of the smartest people in the industry? BillionToOne (Y Combinator S17, one of top YC companies) is looking for a Staff Software Engineer. We’ve built the most accurate cell-free DNA test for pregnant mothers by applying bioengineering and machine learning principles to state-of-the-art molecular testing. Our QCT platform improves the resolution of cell-free DNA testing by >1000x fold and enables novel tests for both prenatal and oncology care. Projects you may work on include: bioinformatics data processing pipelines, laboratory automation tools, and web-based tools to communicate genetic results to patients. This is a highly impactful position with the opportunity to own engineering end-to-end from internal prototypes to widely deployed products directly affecting patients.

If you have experience in full life-cycle development, love seeing your work positively affect your colleagues and patients, and thrive in a fast-paced entrepreneurial environment, this could be a great opportunity for you. In this role, you can make an impact both through many small tools and large product development in a fast-paced environment.

Projects you may work on include:

  • Scaling operational processes for 10x growth in 2 years
  • Expand our tooling and integrate data sources (e.g. logistics, medical records, NextGen DNA sequencers, etc) to help predict problems before they arise; reducing patient frustrations and helping us focus on the hardest problems.
  • Work with Scientists and Process Engineers to create unique, state-of-the-art lab robotics and workflows to set us above the competition.
  • Provide clinical decision support via a pragmatic combination of OCR, UI/UX engineering, and intelligent decision suggestions.

Technologies we use include Django / Django rest framework, Python, Javascript, React, Postgres, AWS: s3, ECR, ECS, Heroku, R.


We offer competitive salary and benefits combined with a truly generous equity package. You will be working on interesting problems with extremely high-impact.

BillionToOne is an equal opportunity employer. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.