Senior Software Engineer, Digital Experiences

About BillionToOne: BillionToOne is a next-generation molecular diagnostics company on a mission to make powerful, accurate diagnostic tests accessible to everyone. Our revolutionary QCT molecular counting technology enhances disease detection resolution by over a thousandfold using cell-free DNA—a breakthrough that’s already transformed the lives of over half a million patients worldwide. We are building products that redefine industry standards in prenatal and cancer diagnostics.

About The Role: We are seeking a high-performing Senior Software Engineer to join our dynamic software engineering team. Software engineers at BillionToOne work in highly collaborative and interdisciplinary teams of clinicians, computational biologists, and other engineers to robustly scale personalized genomic medicine to millions of patients. In this role, you will build a seamless digital experience for clinicians and patients, help digitize laborious workflows, and infuse joyful experiences into pregnancy-related applications. This role is hybrid (onsite 2-3 days/week).

Responsibilities:

• Build and maintain robust applications and systems using React, Typescript, Django, and Postgres.
• Collaborate with product design and management to deliver delightful experiences for patients and providers.
• Foster a knowledge sharing culture through mentorship and collaborative learning.
• Demonstrate a creative mindset by offering innovative solutions to complex challenges.
• Prioritize quality by writing comprehensive unit tests and ensuring adequate test coverage.
• Champion engineering excellence through architectural best practices and thoughtful code reviews.
• Apply a security and compliance mindset ensuring adherence to regulations while protecting sensitive patient information.

Requirements:

• 5+ years of professional software development experience with a proven track record.
• Deep experience with modern frontend technologies, specifically with Typescript, React, and CSS-in-JS libraries.
• Have implemented frontend architecture best practices such as component systems, npm workspaces, Storybook, and Playwright testing.
• Experience with web frameworks such as Django.
• Familiarity with modern AI-driven development practices and tools.
• Excited about working in-person with our team in Menlo Park.

Nice-to-haves:

• Previous startup or entrepreneurial experience.
• Experience in driving products from zero to one.
• Familiarity with healthcare data and standards like FHIR and HL7.
• Interest in engaging with and applying LLMs.

Benefits:

• Competitive base pay range of $187,272 - $208,080 per year.
• Generous equity options offering.
• Corporate bonus program.
• Multiple medical benefit options with 100% premium coverage.
• Generous Family Bonding Leave (16 weeks paid at 100%).
• Free UNITY Complete NIPT testing for employees & spouses.
• Retirement savings program with 4% Company match.
• Latest hardware and on-site amenities including free lunches and EV charging.