Senior Software Engineer

Description

About Karius

Karius is a life science, venture-backed clinical metagenomics company, focused on elevating patient care through microbial insights. We are committed to advancing diagnostic science and technology to optimize the diagnosis and treatment of infectious diseases. Through the use of genomics and AI, we are driven to improve the diagnostic landscape for infectious diseases. Karius delivers unprecedented diagnostic insight detecting microbial cell-free DNA circulating in the body to assist physicians to make rapid treatment decisions.

Position Summary

We are building and operating a unique software stack of cloud infrastructure, software services, APIs, web and mobile interactive interfaces, and AI-driven data analytics pipelines to deliver life-saving results in the highly complex infectious disease landscape. We believe the success of Karius’ products is driven by both our unique technology and the elegance of the software solution.The Senior Software Engineer will play a key role in designing, developing, and maintaining scalable, reliable software solutions that support Karius’ products and mission. This role requires strong technical judgment, thoughtful problem-solving, and close collaboration across engineering, product, scientific, and clinical teams.

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 products Karius offers today are some of the most advanced solutions available to physicians who aim to deliver better care to many otherwise ineffectively treated patients. Our tests are 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: Senior Director, Engineering

Conditions

Primary Responsibilities

Understand user needs, requirements and objectives by collaborating closely with cross-functional groups across Karius, including Engineering, Software Products, Analytics, Lab Operations, and other business partners, developing strong domain expertise to ensure software solutions align with operational and user needs.

Create and maintain technical documentation for system designs, software components, workflows, and operational procedures.

Implementation and end-to-end testing of software solutions and components.

Monitor the performance, reliability, and scalability of software systems and proactively identify opportunities for improvement.

Participate in design reviews and code reviews.

Support production deployments

Troubleshoot and resolve complex production issues, perform root-cause analysis, and implement sustainable corrective and preventive solutions.

Identify technical risks, dependencies, and tradeoffs, and provide recommendations to support informed engineering decisions.

Contribute to the continuous improvement of the engineering lifecycle by collaborating on enhancements to tools, processes, and ways of working.

Develop strong domain expertise to ensure software solutions are scalable, reliable, and aligned with user and operational requirements.

What’s Fun About the Job?

Karius is operating at the edge of what is now known to be possible in 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: Up to 10% for onsite team building activities.

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, lab or clinical environment.

Position Requirements

Bachelor’s degree in Computer Science, Software Engineering, Electrical Engineering, Bioengineering, or a related technical field involving significant coursework in software development, algorithms, or quantitative problem-solving, with 7+ years of relevant software engineering experience; or a master’s degree in a related technical field with 5+ years of relevant software engineering experience.

Experience in healthcare, life sciences, healthcare domains, diagnostic laboratory environments, next-generation sequencing, or other regulated settings.

Experience designing, developing, deploying, and maintaining backend software solutions in production environments.

Advanced knowledge and 3+ years of experience building and maintaining substantial TypeScript and Node.js services in production

Experience contributing to the design and implementation of scalable, reliable, and maintainable software systems

Experience designing and operating microservices-based systems, including event-driven architecture, with a clear understanding of service boundaries, contract evolution, event and message design, error handling across synchronous and asynchronous service calls, and observability

Experience designing PostgreSQL database schemas, with a strong understanding of transactions, indexing, and migration strategy.

Working knowledge of containerized, cloud-based systems using technologies such as Docker, Kubernetes, GraphQL, and AWS or equivalent cloud platforms.

Experience with unit and end-to-end testing frameworks such as Jest, Vitest, Playwright, or similar, with strong test design skills and the ability to translate acceptance criteria or user stories into a balanced coverage strategy across unit, integration, and end-to-end testing.

Strong knowledge of software engineering practices, including code review, automated testing, source control, continuous integration, deployment, monitoring, observability, and technical documentation.

Demonstrated ability to independently lead complex technical work, troubleshoot production issues, and deliver high-quality solutions across the software development lifecycle.

Production experience with Kafka or a comparable event-streaming platform is preferred, including topic design, partition strategy, consumer group behavior, idempotency, ordering guarantees, and handling delayed, failed, or unprocessable messages; Confluent experience is a plus.

Experience operating services in AWS or similar environments is preferred, including the ability to navigate services such as EKS, RDS, S3, CloudWatch, and IAM and troubleshoot issues across application and infrastructure boundaries.

Hands-on experience using modern AI coding tools such as Claude, Cursor, GitHub Copilot, or similar to accelerate development, code review, testing, and documentation is preferred.

Personal Qualifications

Demonstrated commitment to engineering excellence, with a strong focus on testability, maintainability, reliability, and long-term system quality.

Strong written communication skills, with the ability to develop clear design documents, pull request descriptions, test cases, and technical documentation. Strong communication and collaboration skills, with the ability to work effectively with engineering and cross-functional stakeholders.

Strong problem-solving and analytical skills, with the ability to identify root causes, evaluate tradeoffs, and develop practical, scalable solutions to complex technical challenges.

Ability to troubleshoot issues across multiple systems, services, applications, and integration points while collaborating effectively across teams.

Ability to operate effectively in ambiguous environments by asking thoughtful questions, identifying assumptions and dependencies, and helping define a clear path forward.

Growth-oriented learning mindset, with the curiosity and adaptability to learn new technologies, deepen domain expertise, seek feedback, and continuously improve.

Ability to thrive in a fast-paced environment, effectively managing shifting priorities, competing demands, and tight deadlines while maintaining quality and attention to detail.