Skip to contentSkip to footer
  • Community
  • Jobs
  • Companies
  • Salaries
  • For employers
      Notifications

      Loading...

      Elevate your career

      Discover your earning potential, land dream jobs, and share work-life insights anonymously.

      employer cover photo
      employer logo
      employer logo

      BillionToOne

      Engaged employer

      About
      Reviews
      Pay and benefits
      Jobs
      Interviews
      Interviews
      Related searches: BillionToOne reviews | BillionToOne jobs | BillionToOne salaries | BillionToOne benefits
      BillionToOne interviewsBillionToOne Head of Product Management, Oncology interviewsBillionToOne interview


      Glassdoor

      • About / Press
      • Awards
      • Blog
      • Research
      • Contact Us
      • Guides

      Employers

      • Free Employer Account
      • Employer Centre
      • Employers Blog

      Information

      • Help
      • Guidelines
      • Terms of Use
      • Privacy and Ad Choices
      • Do Not Sell Or Share My Information
      • Cookie Consent Tool
      • Security

      Work With Us

      • Advertisers
      • Careers
      Download the App

      • Browse by:
      • Companies
      • Jobs
      • Locations
      • Communities
      • Recent posts

      Copyright © 2008-2026. Indeed, Inc. "Glassdoor," "Worklife Pro," "Bowls" and logo are proprietary trademarks of Indeed, Inc.

      Company Bowl sample

      Want the inside scoop on your own company?

      Check out your Company Bowl for anonymous work chats.

      Bowls

      Get actionable career advice tailored to you by joining more bowls.

      Followed companies

      Stay ahead in opportunities and insider tips by following your dream companies.

      Job searches

      Get personalised job recommendations and updates by starting your searches.

      Head of Product Management, Oncology Interview

      3 Jul 2026
      Anonymous interview candidate
      Del Mar, CA
      No offer
      Negative experience
      Easy interview

      Application

      I applied online. I interviewed at BillionToOne (Del Mar, CA) in Mar 2026

      Interview

      The interview process is extensive and one-sided by design. It begins with an online screening quiz testing statistical and clinical knowledge, followed by a take-home assignment, and then five separate interviews spanning R&D, sales, operations, and two rounds with the CPO. Candidates are expected to demonstrate deep scientific literacy, strategic thinking, and domain expertise at every stage ...and expected to do so graciously and without complaint. What you will not experience is any reciprocal curiosity. No one will ask what drives you, what kind of leadership environment you thrive in, or what you need to do your best work. The process is designed to extract signal from candidates, not to evaluate fit in any meaningful two-way sense. After completing all of the above, I waited weeks for an update, followed up directly, and received silence. No rejection, no timeline, no courtesy email. For a company that presents itself as transparent and people-first, the gap between that brand and the lived candidate experience is significant. If you make it far in this process, manage your expectations accordingly.

      Interview questions [3]

      Question 1

      Question 1 — Sensitivity & Specificity / Bayesian PPV "A new diagnostics company markets a test with 99% sensitivity and 99% specificity for Disease X, which occurs in 1 in 10,000 people. You receive a positive result. What is the probability you actually have the disease?" Candidates are expected to work through the Bayesian math and arrive at a PPV of approximately 0.98% — and to understand the implications for population-level screening recommendations. Question 2 — Retrospective vs. Prospective Study Design "Grail's Galleri assay showed 51.5% sensitivity in CCGA-3 but only 20.7–28.9% in the PATHFINDER prospective study. The assay itself did not change. What explains the drop?" Candidates are expected to discuss spectrum bias,
      1 Answer

      Question 2

      Walk me through your background Tell me about a time you had to manage risk and change project direction under resource constraints Tell me about a time you had to manage a QC error or failure How did you scale up a test? Tell me about a failure you had to rectify. What question should I ask you?
      Answer question

      Question 3

      what's your POV on oncology testing, how do you gain unique insights, give an example where an insight led to a decision.
      Answer question