Senior Software Engineer

Karius is a clinical metagenomics company developing diagnostic products for infectious diseases. The Senior Software Engineer designs, develops, tests, and maintains scalable software systems, collaborating with engineering, product, scientific, clinical, and operational teams to support Karius’ products and users.

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

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
• 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
• 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