Principal 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 outcomes while making healthcare more affordable.

Onos recently closed a $6M round with top-tier investors and is already working with some of the nation’s largest health plans, signing its first national plan just months after launch.

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 a capable technical leader who is motivated to meaningfully improve the way healthcare is administered in the United States. You'll take ownership of developing a significant part of the Onos platform through hands-on development and technical leadership. As an early team member, you'll work closely with our founding team while helping to build and lead a growing engineering team. This role is a hybrid role based in San Francisco, where you'll be expected to work at our office in person at least once a week.

What you'll be doing at Onos :

Architecting and implementing major platform components to provide actionable insights and recommendations to health plan administrators

Develop robust integrations with health care systems and build scalable data pipelines for health records, provider directories, and claims processing

Work closely with ML / LLM engineers to build and optimize models for behavioral and mental health

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 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 sophisticated anomaly detection systems to identify fraudulent or abusive providers

Build ML pipelines to analyze large amounts of medical records 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 you'll have the freedom to evaluate and adopt cutting-edge technologies as we scale.

Languages / Frameworks : Python, Django, Django Ninja, Celery / Celery Beat

Database / Storage : PostgreSQL (AWS RDS), S3

Infrastructure / Systems : AWS (ECS, Bedrock, etc.), Docker, Terraform

Development Tools : Github, Jira, Cursor

What we're looking for :

5+ years experience building robust and well-architected software applications

Customer obsessed and motivated to make an impact in the healthcare space

Expertise with data engineering and backend web development practices

A hands‑on leader and collaborative team player with an attention to the details

Bonus points if you have :

Significant experience working with healthcare data and with HIPAA best practices

Worked with machine learning and large language models for end‑user applications

Built and managed teams of engineers on major software projects

Benefits and Perks

Flexible hybrid arrangement : 1-2 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

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.

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