Senior Software Engineer, Backend

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

• 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.

Compensation Range: $180K - $240K