Senior Software Engineer (Developer/SDET)
Karius
Software Engineering
Redwood City, CA, USA
Posted on Oct 11, 2025
About Karius
Karius is a venture-backed life science startup that is transforming the way pathogens and other microbes are observed throughout the body. By unlocking the information present in microbial cell-free DNA, we're helping doctors quickly solve their most challenging cases, providing industry partners with access to 1000’s of biomarkers to accelerate clinical trials, discovering new microbes, and reducing patient suffering worldwide.
Position Summary
We are seeking a Senior Software Engineer (Developer / SDET hybrid) to design, build, and test the analytical software systems that power the Karius test. Our team develops AI-driven bioinformatics and data pipelines to deliver life-saving results in the highly complex infectious disease landscape. In this role, you will drive both system development and improvements in testability, automation, and validation across the software lifecycle. You will collaborate closely with other engineers, bioinformaticians, product managers, and quality stakeholders to ensure our systems are robust, reliable, and compliant. Your work will span from writing production code to building test frameworks and validation tools - directly contributing to the accuracy, scalability, and trustworthiness of the Karius platform, and ultimately helping physicians treat patients more effectively.
Why Should You Join Us?
Karius aims to conquer infectious diseases through innovations around genomic sequencing and machine learning. The company’s platform is already delivering unprecedented insights into the microbial landscape, providing clinicians with a comprehensive test capable of identifying more than a thousand pathogens directly from blood, and helping industry accelerate the development of therapeutic solutions. The Karius test we provide today is one of the most advanced solutions available to physicians who aim to deliver better care to many otherwise ineffectively treated patients. Our test is the result of some incredible work done by our scientists, statisticians, engineers, and physicians, all driven by the same mission. You, as part of the Karius team, will be able to see how directly your work has a life-changing impact on people, and at scale.
Reports to: Director, Analytical Systems & Data Insights
Location: Redwood City, CA (Hybrid)
Primary Responsibilities
Software Development (Back-End Focus) - Drive the design and implementation of production software systems that power Karius’s analytical pipelines.
• Design, build, and maintain back-end software systems spanning analytical pipelines, APIs, data processing services, and supporting infrastructure.
• Implement scalable, reliable, and secure services for ingesting, storing, and processing large volumes of genomic data.
• Collaborate with bioinformaticians on integrating algorithms and analytical pipelines into production systems.
• Contribute to architecture and design reviews, emphasizing performance, reliability, and maintainability.
• Contribute to peer code reviews, design discussions, and sprint planning as part of the team.
Software Testing - Build and sustain the frameworks and processes that ensure our systems meet the highest standards of reliability, performance, and compliance.
• Develop and maintain test automation frameworks and tools (e.g., Pytest, Postman, custom command-line tooling/scripts) to ensure comprehensive coverage of unit, integration, regression, and system-level testing.
• Translate requirements and specifications into well-structured test cases and test plans, ensuring traceability between requirements, risks, and test cases using modern tools and processes.
• Support the execution and documentation of verification and validation (V&V) activities, ensuring compliance with regulated software development practices.
• Advocate for testability and quality throughout the software lifecycle, helping shape designs that are easier to validate and maintain.
What’s Fun About the Job?
Karius is operating at the edge of what is now known to be possible in infectious disease diagnostics. With that, comes a wave of new and incredible challenges and opportunities. To deliver on that value, you will be tapping into some of the most advanced technologies, architecting and innovating where the current solutions simply don't suffice. You will get to see how much your work really matters.
Travel: (1x week minimum) Onsite for all team meetings.
Physical Requirements
Subject to extended periods of sitting and/or standing, vision to monitor and moderate noise levels. Work is generally performed in an office environment.
Position Requirements
• BS or MS degree in Computer Science, Software Engineering, Electrical Engineering, Bioengineering, or a related technical field involving algorithms or coding (e.g., physics or mathematics).
• 5+ years of experience designing, developing, and maintaining production software systems (Python preferred), ideally with experience in regulated environments (e.g., healthcare, life sciences).
• Experience with cloud platforms (e.g., AWS, Azure, GCP) and developing distributed cloud-based systems using modern technologies and flows (e.g., Docker, Kubernetes, Git/GitHub, CI/CD, Kafka, GraphQL).
• Experience across the full software development lifecycle, including project management, requirements traceability, and test automation using Python and modern frameworks (e.g., Pytest, Postman, Playwright, Selenium).
• Familiarity with bioinformatics tools and genomic data formats is a strong plus.
• Familiarity with regulations pertaining to IVD and/or LDT development (e.g., 21 CFR Part 11, 21 CFR Part 820, CAP/CLIA, NYS DOH) and related standards (e.g., IEC 62304, ISO 13485, ISO 14971) is a strong plus.
Personal Qualifications
• Passionate, purpose-driven, and excited about Karius’ mission.
• Strong organizational and time management abilities.
• Demonstrated ability to tackle complex problems.
• Ability to work independently but also be an excellent team player.
• A role model for Karius culture and values, with a commitment to integrity, quality, and excellence.
Disclaimer
The above job description is intended to describe the general nature and level of work being performed by individuals assigned to this position. It is not intended to be an exhaustive list of all duties, responsibilities, and skills required. Responsibilities and duties may change or be adjusted to meet the needs of the company, and additional duties may be assigned as necessary. The job description is subject to change at any time at the discretion of Karius.
Equal Opportunity Employer
At Karius, we value a diverse and inclusive workplace and provide equal employment opportunities for all applicants and employees, and are committed to honor and invest in the full diversity of people, in our hiring, recruiting, and development of employees across the Company. All qualified applicants for employment are encouraged to apply and will be considered without regard to an individual’s race, color, sex, gender identity, and gender expression (including transgender individuals who are transitioning, have transitioned, or are perceived to be transitioning to the gender with which they identify), religion, age, national origin or ancestry, citizenship, physical or mental disability, medical condition, family care status, marital status, domestic partner status, sexual orientation, genetic information, military or veteran status, or any other basis protected by federal, state or local laws. If you are unable to submit your application due to a disability, please contact us at recruiting@kariusdx.com and we will accommodate qualified individuals with disabilities.