Principal Software Engineer (Backend)

Position Overview

Onos Health’s mission is simple but ambitious – to ensure every healthcare dollar goes toward delivering the highest quality care. With 30% of total U.S. healthcare spending wasted due to ineffective care and administrative burdens, Onos is building the largest AI-driven healthcare data platform to help payers make faster, more accurate decisions and guide members to the right care.

As a category-defining company, Onos has recently closed a $6M funding round and is partnering with some of the nation’s largest health plans. We are now seeking a capable technical leader to take ownership of developing significant parts of our platform through hands-on development and technical leadership. This early team member role is a hybrid opportunity based in Location: San Francisco, where you will work in person at our office at least once a week.

Why Onos? Meaningful impact, direct collaboration with experienced founders, a transparent culture, significant ownership from day one, and the opportunity to build a fast-growing healthcare AI company.

Key Responsibilities

• Architect and implement major platform components to deliver actionable insights and recommendations to health plan administrators.
• Develop robust integrations with healthcare systems and build scalable data pipelines for health records, provider directories, and claims processing.
• Collaborate with ML/LLM engineers to build and optimize models for behavioral and mental health.
• Establish engineering best practices and technical foundations to support future team growth.
• Shape the technical roadmap through key architectural decisions and by influencing the company’s product strategy.
• Develop an intelligent engine that ingests complex medical standards of care documents and assesses provider adherence to guidelines.
• Design and implement sophisticated anomaly detection systems to identify fraudulent or abusive providers.
• Build machine learning pipelines to analyze large volumes of medical records and automate clinical recommendations.
• Scale systems to process millions of healthcare records while upholding strict security and compliance standards.

Required Qualifications

• 5+ years experience building robust and well-architected software applications.
• Customer-obsessed and motivated to make a significant impact in the healthcare space.
• Expertise in data engineering and backend web development practices.
• A hands-on leader and collaborative team player with strong attention to detail.

Preferred Qualifications

• Significant experience working with healthcare data and a deep understanding of HIPAA best practices.
• Experience with machine learning and large language models for end-user applications.
• Proven track record in building and managing engineering teams on major software projects.

Benefits & Perks

• Flexible hybrid arrangement: 1-2 days/week at the San Francisco office (financial district) with a remote-first culture.
• Unlimited vacation policy.
• Paid parental leave.
• Medical, dental, and vision insurance.
• Pre-tax commuter benefits.
• 401(k) plan.
• Significant equity as an early employee.
• Ground-floor opportunity to help build a team and shape company culture.
• Regular team events and offsites.
• Company-provided equipment and home office setup.