Summer 2026

Software Engineer Intern

Posted on 6/3/2026

BillionToOne

BillionToOne

501-1,000 employees

QCT-based molecular diagnostics for prenatal, oncology

Compensation Overview

$34.62 - $57.69/hr

Menlo Park, CA, USA

Hybrid

Hybrid role; 2-3 days per week on-site in Menlo Park, CA.

Bachelor's, Master's

Category
Software Engineering (1)
Required Skills
Python
SQL
Web Development

Get referred to BillionToOne

See people who can refer or advise you

Requirements
  • Currently enrolled in a Bachelor's or Master's degree program in Computer Science or related field
  • Demonstrated programming experience with Python through coursework or projects
  • Basic understanding of databases (SQL) and web development concepts
  • Strong problem-solving skills and eagerness to learn
  • Clear written and verbal communication skills
  • Available for full-time summer internship (10-12 weeks)
  • Excited about working in-person with our team in Menlo Park (2-3 days/week)
  • Passionately curious about the fields of healthcare and biotechnology
Responsibilities
  • Write clean, well-documented code following team standards and best practices
  • Participate in code reviews and contribute to technical discussions
  • Create and maintain comprehensive test suites for your code
  • Document your work and contribute to technical documentation
  • Present your projects and findings to the team
Desired Qualifications
  • Previous project experience (personal, academic, or hackathon projects)
  • Familiarity with any web framework (Django, Flask, etc.)
  • Basic understanding of version control (Git)
  • Experience working with LLMs (GPT, Claude, etc.)
  • Experience working with REST APIs
  • Basic understanding of cloud services concepts
  • Experience with prompt engineering or LLM application development

BillionToOne provides molecular diagnostic testing for prenatal screening and cancer monitoring. Its QCT technology detects and measures DNA variations at a single base-pair level, enabling precise analysis across the three billion DNA letters. The main products, Northstar Select and Northstar Response, are tests that help doctors choose the best first-line therapy and track how well treatment is working, respectively. The company markets these services to healthcare providers who perform the tests and use the results to guide patient care. Unlike some rivals, BillionToOne emphasizes high-resolution DNA assessment and scalable diagnostic services through provider partnerships, aiming to improve accuracy, speed, and access. Its mission is to make molecular testing more accurate, efficient, and accessible to all, driven by growth, equality, and teamwork.

Company Size

501-1,000

Company Stage

IPO

Headquarters

Menlo Park, California

Founded

2016

Get referred to BillionToOne

See people who can refer or advise you

Simplify Jobs

Simplify's Take

What believers are saying

  • Q2 2026 revenue hit $109.4 million, up 64%, with positive operating income.
  • Oncology revenue jumped 176% in Q2 2026 after Northstar Select and Response expansion.
  • Management reaffirmed 2026 revenue guidance of $450 million to $465 million, signaling execution confidence.

What critics are saying

  • Illumina sued BillionToOne on May 7, 2026 over prenatal-test patent infringement.
  • Prenatal pricing depends on reimbursement; any payer pushback hits the $94.2 million franchise.
  • Competitors like Natera and Guardant can outspend BillionToOne on sales and evidence.

What makes BillionToOne unique

  • Unity Complete and Northstar use single-molecule cfDNA counting for rare-variant detection.
  • August 17, 2026 launched 130-gene fetal panel, the largest single-gene NIPT panel.
  • September 1, 2026 Northstar Origin added tissue-of-origin prediction without extra blood draws.

Help us improve and share your feedback! Did you find this helpful?

Benefits

Competitive pay

Retirement savings package

Parental leave

Free snacks & lunches

Medical, dental, & vision premiums

On campus perks

Free-on-site EV charging

Growth & Insights and Company News

Headcount

6 month growth

0%

1 year growth

0%

2 year growth

0%
PR Newswire
Sep 1st, 2026
BillionToOne launches Northstar Origin liquid biopsy test to identify cancer tissue of origin

BillionToOne has launched Northstar Origin, a liquid biopsy add-on test that predicts tissue of origin from circulating cell-free DNA for patients with cancer of unknown primary or uncertain cancer diagnosis. The test requires no additional tissue or separate blood draws beyond what's already collected for therapy selection. In a validation study of 1,578 patients, Northstar Origin identified the correct tissue of origin as its top prediction in 87% of cases and within its top three predictions in 91% of cases. The classifier was developed using 6,025 blood samples from advanced cancer patients. The company also expanded its Northstar Select panel from 84 to 102 genes, adding 18 new genes including MTAP deletion. The test is designed to help community oncologists make diagnostic decisions, as roughly 3-5% of new cancer diagnoses present as cancer of unknown primary.

Yahoo Finance
Aug 28th, 2026
BillionToOne CTO sells $1M in shares under pre-planned trading arrangement

David Tsao, co-founder and chief technology officer of BillionToOne, sold 10,000 shares of Class A Common Stock for $1 million on 25 August 2026. The transaction involved a cashless exercise of fully vested stock options at $2.80 per share, with the resulting shares sold at a weighted average price of $100. The sale was executed under a Rule 10b5-1 trading plan adopted in March 2026, indicating it was pre-scheduled rather than discretionary. Tsao retains 1,000 direct shares and 580,000 stock options. BillionToOne, a Menlo Park-based molecular diagnostics company, reported second-quarter revenue of $109.4 million, representing 64% year-over-year growth. The company has a market capitalisation of $4.4 billion and generated $397.4 million in trailing 12-month revenue with $33.5 million in net income.

Yahoo Finance
Aug 6th, 2026
BillionToOne reports $109.4M Q2 revenue, up 64% year-over-year, reiterates 2026 guidance

BillionToOne, a molecular diagnostics company, reported second-quarter 2026 revenue of $109.4 million, up 64% from $66.6 million in the same period last year. Prenatal clinical testing revenue reached $94.2 million, whilst oncology testing revenue surged 176% to $13.7 million. The company delivered 196,000 tests during the quarter, a 35% increase year-over-year. Gross profit margin improved to 70% from 65%. BillionToOne posted operating income of $5.5 million, compared to a $1.6 million loss in Q2 2025. The firm reiterated its full-year 2026 revenue guidance of $450 million to $465 million, representing 48% to 52% growth over 2025. BillionToOne announced plans to expand its Unity Fetal Risk Screen with a 130-gene panel launching 17 August 2026.

Yahoo Finance
Aug 6th, 2026
BillionToOne revenue surges 64% to $109M as oncology jumps 176% and prenatal grows 56%

BillionToOne reported strong second-quarter results for 2026, with total revenue reaching $109.4 million, up 64% year-over-year. Prenatal revenue rose 56% to $95.8 million, while oncology revenue surged 176% to $13.7 million. The company achieved gross margins of 70.5%, up 5 percentage points from the previous year. BillionToOne posted operating income of $5.5 million and net income of $8.1 million, or $0.15 per diluted share. Test volumes increased 35% year-over-year to approximately 196,000 tests, with average selling prices rising 21% to $551 per test. The company generated $9.1 million in cash from operations and $5.1 million in free cash flow. BillionToOne maintained its full-year 2026 revenue guidance of $450 million to $465 million.

GenomeWeb
Aug 5th, 2026
BillionToOne to launch NIPT, liquid biopsy add-ons as Q2 revenue rises 64 percent.

BillionToOne to launch NIPT, liquid biopsy add-ons as Q2 revenue rises 64 percent. NEW YORK - BillionToOne said on Wednesday that its second-quarter revenue grew 64 percent year over year on the back of strong prenatal and oncology clinical testing sales. Get the full story with GenomeWeb Premium. Only $95 for the first 90 days. Full site access Interest-based email alerts Premium Access - Trial Offer $95.00 for 3 month Already a GenomeWeb member? LoginLogin

INACTIVE