Senior Software Engineer (Backend)

About Onos Health Onos Health’s mission is simple but ambitious: ensure every healthcare dollar goes toward delivering the highest quality care. Today, 30% of total U.S. healthcare spending is wasted due to ineffective care and administrative burden caused by misalignment between providers and payers. Onos is addressing this by building the largest AI-driven healthcare data platform. Our models enables payers to make faster, more accurate decisions across their populations. By guiding members to the right care, Onos is channeling more dollars to high-quality care that drives better outcomes while making healthcare more affordable. Onos is well-funded by some of the best healthcare investors and is working with the nation’s largest health plans. Come join a category-defining company and help reimagine healthcare for the better. Why Onos? Meaningful impact: Help fix what is fundamentally broken in healthcare Direct collaboration: Work alongside experienced founders with deep healthcare and data expertise Culture: Join a high-performing, transparent, and results-oriented team Ownership: Significant responsibility and autonomy from day one Opportunity: Play a pivotal role in building a fast-growing, category-defining healthcare AI company The Role We're seeking an experienced Senior Backend Engineer who is motivated to meaningfully improve the way healthcare is administered in the United States. You'll take ownership in helping develop a significant part of the Onos platform through hands-on development. This role is a hybrid role based in San Francisco, where you'll be expected to work at our office in person 2-3 times a week. What you'll be doing at Onos: Architect workflows that utilize AI/ML to process claims, medical records and other data types to evaluate the optimal care path for health plan members Lead the integration and rollout of the Onos platform for new enterprise customers to provide actionable insights and recommendations to health plan administrators Own end-to-end development of new features and functionality for the Onos platform, including requirements gathering, scoping, architecting, implementation and testing to deliver timely and high quality outcomes Establish engineering best practices and technical foundations for future team growth Shape our technical roadmap, make key architectural decisions, and influence the company's product and technical strategy Technical Challenges At Onos: Develop an intelligent engine that ingests complex medical standards of care documents and evaluates provider adherence to guidelines Design and implement robust and extensible systems to easily support many different kinds of enterprise workflows and integrations Build AI/ML pipelines to analyze handwritten clinical notes, accurately extract important medical information, and automate recommendations for clinical reviewers Scale our systems to process millions of healthcare records while maintaining strict security and compliance requirements Tech Stack: At Onos, we work with a modern tech stack where we continuously evaluate and adopt cutting-edge technologies as we scale. Infrastructure/Systems: AWS (ECS, Bedrock, Glue, etc.), Docker, Github Actions, Terraform Languages/Frameworks Backend: Python, Django, Celery / Celery Beat, django-ninja, django-tenants Frontend: NextJS, Typescript, Tanstack Query, Shadcn UI, Zod, Nuqs Database/Storage: PostgreSQL (AWS RDS), S3, Clickhouse Development Tools: Github, Jira, Claude Code, CoderabbitAI, Tusk What we're looking for: 5+ years experience building software applications Prior experience leading engineering teams as a tech lead or engineering manager Strong product sense and system design skills with a track record of defining clear requirements, test scenarios, and acceptance criteria for complex systems Customer obsessed and motivated to make an impact in the healthcare space A hands-on technical leader who can architect robust and extensible systems, establish best practices with AI coding tools, and ship high quality production code Bonus points if you have: Worked with machine learning and large language models for end-user applications Hands-on experience navigating healthcare data formats such as EDI X12, HL7, FHIR, and custom payer flat files Benefits and Perks Flexible hybrid arrangement: 2-3 days/week at San Francisco office (Financial District), remote-first culture Unlimited vacation policy Paid parental leave Medical, dental, and vision insurance Pre-tax commuter benefits 401(k) Significant equity as an early employee Direct mentorship from experienced founders Ground-floor opportunity to help build a team and culture Regular team events and offsites Company-provided equipment and home office setup We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.