Back End Developer

Day One Partners; San Francisco (CA); Hybrid; USD 140,000 - 190,000; Full time

Job summary

Day One Partners is hiring a Senior Backend Engineer to build and scale customer-facing AI products for healthcare providers. You will own backend development, from architecture to production, and collaborate closely with product and customer teams.

The role emphasizes shipping quickly with strong technical judgment, reliability, and the ability to work across Python-based services (Flask/Django/FastAPI) on a hybrid schedule in Mountain View or San Francisco.

Qualifications

• 3+ years of professional software engineering experience.
• Experience building and operating production software systems.
• Familiarity with backend frameworks such as Flask, Django, or FastAPI.
• General understanding of containers and cloud infrastructure, including Docker and Kubernetes.
• Strong ownership, communication, and product sense.

Responsibilities

• Build and scale backend systems for large healthcare customers.
• Develop production services using Python with Flask, Django, or FastAPI.
• Own projects end-to-end from architecture to deployment and reliability.
• Build infrastructure to support rising usage and demand.
• Collaborate with customers and internal teams to diagnose problems and ship solutions quickly.
• Maintain high observability, monitoring, and reliability in production.

Skills

Python

Flask

Django

FastAPI

Education

Bachelor's or Master's in CS/Engineering

Tools

Docker

Kubernetes

Cloud infrastructure

Job description

Location: Mountain View or San Francisco, CA

Work Model: Hybrid: 3 days on sight, 2 remote

Employment Type: Full Time

About the Company

We're partnering with a high-growth Series E healthcare AI company building technology designed to fundamentally improve how healthcare is delivered and operated.

The company recently raised $70M, has raised more than $800M in total funding, and is backed by leading investors including Sequoia, General Catalyst, Y Combinator, Lux Capital, Greenoaks, and others.

The business has significant market traction and has grown 300%+ year over year for the past two years. Its technology is already used by 500,000+ clinicians across hundreds of healthcare organizations, supports 100M+ patient interactions, and processes more than $10B through its systems.

Healthcare represents a $4.5T market, with more than $500B spent annually on administrative costs, creating an enormous opportunity for AI to reshape clinical and operational workflows. The company is entering its next phase of growth with new products, expanding customer adoption, and significant engineering challenges still ahead.

About the Role

We're looking for a Senior Backend Engineer to help build and scale customer-facing AI products used by healthcare providers every day.

This is a highly hands-on role for an engineer who enjoys moving quickly, owning meaningful technical problems, and building reliable production systems at scale. You'll work across backend application development and infrastructure, partner closely with customers and product teams, and take projects from early thinking through production.

There is still substantial opportunity to influence architecture, engineering practices, product direction, and the technical foundation of a rapidly scaling platform.

What You'll Do

• Build and scale backend systems supporting some of the largest healthcare organizations in the country
• Develop production services primarily using Python, including frameworks such as Flask, Django, and FastAPI
• Own projects end to end, from architecture and implementation through deployment and production reliability
• Build infrastructure capable of supporting rapidly increasing product usage and customer demand
• Work with Docker, Kubernetes, cloud infrastructure, and modern deployment environments
• Improve observability, alerting, metrics, monitoring, and software reliability
• Work directly with customers and internal teams to diagnose problems and quickly ship solutions
• Operate in a high-ownership engineering environment that values fast execution and strong technical judgment

What We're Looking For

• Bachelor's or Master's degree in Computer Science, Engineering, or a related field, or equivalent professional experience
• 3+ years of professional software engineering experience
• Experience building and operating production software systems
• Familiarity with backend frameworks such as Flask, Django, or FastAPI
• General understanding of containers and cloud infrastructure, including Docker and Kubernetes
• Experience with areas such as:
• Monitoring and alerting
• Metrics and observability
• Production reliability
• Scalable backend infrastructure
• Experience in environments where engineers are expected to ship quickly and take significant ownership
• Strong product sense and attention to customer needs
• High level of motivation, ownership, and attention to detail
• Strong communication and leadership skills

Why This Opportunity

This is an opportunity to join a company that already has meaningful scale while still offering the ownership and pace typically associated with much earlier-stage startups.

You'll be joining a fast-growing engineering organization tackling technically difficult problems in one of the largest industries in the world, with the opportunity to build products used directly by clinicians and healthcare organizations at significant scale.

Growth: 300%+ YoY for the past two years

Scale: 500K+ clinicians | 100M+ patient interactions | $10B+ flowing through the platform

Location: Mountain View or SF, Hybrid (3 days on sight)