Senior Software Engineer, Digital Experiences (Prenatal)

BillionToOne (YC S17) is a molecular diagnostics company founded in 2016 with 300+ employees. The firm has achieved unicorn status with over $400M in funding and $125M ARR. Their QCT technology enhances disease detection resolution by over a thousandfold using cell-free DNA. The company serves prenatal and oncology markets.

As a Senior Software Engineer, Digital Experiences (Prenatal), you will:

• Build applications using React, TypeScript, Django, and PostgreSQL
• Collaborate with product and design teams for patient/provider experiences
• Mentor colleagues and foster knowledge sharing
• Write comprehensive unit tests with strong coverage
• Champion engineering excellence and security practices

Required Qualifications:

• 5+ years professional software development
• Deep expertise in TypeScript, React, CSS-in-JS libraries
• Frontend architecture experience (component systems, Storybook, Playwright)
• Django web framework knowledge
• Familiarity with modern AI-driven development practices

Tech Stack: Python, Django, PostgreSQL, React, TypeScript, AWS, Salesforce, and emerging AI-assisted coding environments (e.g., Cursor, GitHub Copilot, Claude Code)

Benefits:

• 16 weeks fully paid parental leave
• 100% employee health insurance premiums (select plans)
• 4% 401(k) match
• On-site gym, restaurant, EV charging
• Daily catered lunches

Salary: $190,081 - $211,201 base; $297,321 total compensation Hybrid: 2-3 days/week onsite in Menlo Park, CA