Do you want to join one of the fastest-growing molecular diagnostics startups and be a pioneer for an industry-leader who is impacting the lives of millions?

Come help lead our world-class QARA team and bring your career to the next level working alongside some of the most inspiring leaders in the industry.

BillionToOne, ranked at the top 5% of Y Combinator companies with $300M+ in funding from prominent VC firms, has developed a DNA molecular counter that increases cfDNA diagnostic resolution by over 1,000 fold. BillionToOne's first product, UNITY™ is the first and only non-invasive prenatal test that can directly screen an unborn baby and assess its risk for common and severe recessive gene disorders and chromosomal abnormalities, as well as fetal sex and fetal antigens, from a single tube of blood from the pregnant mother without paternal testing.

In 2023, BillionToOne launched two liquid biopsy products that will markedly improve oncology treatment and care. With Northstar Select™, clinicians will be able to select cancer therapies that will be most effective to each patient based on their individual genetic makeup. Northstar Response™ will enable clinicians to monitor a patient’s early response to these cancer therapies, by measuring minute changes in their ctDNA, which can reduce ineffective treatments and unwanted toxicity, lower costs, and substantially improve clinical outcomes.

As the Senior Quality Engineer, you will have a strong background in the LDT environment, with expertise in lab practices, bioinformatics, report automation, assays, and reagents. Additionally, you will possess a deep understanding of quality tools and practices to ensure the highest standards of our products and services. In this role you will be responsible for identifying, developing, and executing process improvements and will work closely with cross-functional stakeholders across BillionToOne (e.g. Lab Operations, R&D, Bioinformatics, Software Engineering). You will lead the analysis of data to identify improvement initiatives and will execute those process improvements from initial requirements gathering to go-live and further continuous improvement. This role is an onsite position in our brand new, state-of-the-art, 90,000 square foot facility in Union City, CA and will report directly to the Vice President of QARA.


  • Perform statistical analysis and trending of quality data to identify improvement opportunities and monitor the effectiveness of quality initiatives.
  • Conduct root cause analysis and implement corrective and preventive actions (CAPA) to address non-conformances and drive continuous improvement.
  • Collaborate with cross-functional teams, including laboratory operations, bioinformatics, software engineering, and assay development, to identify and implement improvements.
  • Develop and maintain quality documentation, including SOPs, validation protocols, and quality reports.
  • Provide training and guidance to team members on quality tools, practices, and regulatory requirements.
  • Develop, implement, and maintain quality systems and processes in compliance with regulatory requirements for LDTs.
  • Stay current with industry trends, regulations, and best practices related to LDTs and molecular diagnostics.


  • Bachelor's degree in a scientific or technical field (e.g., biology, chemistry, biomedical engineering, manufacturing or related discipline); advanced degree preferred
  • Minimum of 5 years of experience within the LDT industry and familiarity with relevant regulations and guidelines, such as CLIA, CAP, and state-specific requirements for LDTs
  • Strong knowledge of lab practices, bioinformatics, report automation, assays, and reagents
  • Expertise in quality tools and practices, including root cause analysis, CAPA, and statistical analysis
  • Experience with quality management systems and continuous improvement methodologies (e.g., Lean, Six Sigma)
  • Ability to work independently and cross-functionally to implement systems and processes
  • Creative problem solving, detail oriented, and critical thinker characteristics required
  • Proven ability to drive results to established timelines
  • Proven ability to communicate effectively both in writing and verbally
  • Must be comfortable and effective acting as a catalyst for change 


  • Experience with ISO13485 and FDA CFR a plus

Benefits And Perks:

  • Working with a team of ‘rockstars’ who bring out the best in everyone
  • Open, transparent culture that includes weekly Town Hall meetings
  • The ability to indirectly or directly change the lives of hundreds of thousands patients
  • Multiple medical benefit options; employee premiums paid 100% of select plans, dependents covered at 80%
  • Extremely generous Family Bonding Leave for new parents (16 weeks, paid at 100%)
  • Retirement savings program including a 4% Company match
  • Free daily on-site lunches provided from top eateries
  • Latest and greatest hardware (laptop, lab equipment, facilities)
  • A variety of perks on campus (state of the art gym, restaurant)
  • Free on-site EV charging (compatible with all EVs, including Tesla)

At BillionToOne, we are proud to offer a combination of a (1) base pay range (actual amount offered is based experience and salary/equity options split that the candidate chooses) (2) generous equity options offering, on top of (3) industry leading company benefits (free healthcare options, 401k match, very generous fully paid parental leave etc.).

For this position, we offer a base pay range of $150,000-$175,000 per year. 

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.

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