Senior Software Engineer, Product

lunar - part of +koo; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Lunar is a stealth technology company building AI-powered software to transform health systems. We are rebuilding the hospital software stack from scratch, with Elixir at the core, to power clinicians and patients with fast, reliable insights.

Join a mission-driven team solving hard problems—cloud-native architecture, fine-grained access control for clinical data, 24/7 reliability, and real-time integration with medical devices—while shaping the future of healthcare software.

Qualifications

• Minimum of 10 years of professional software engineering experience.
• Proficiency with OO and functional programming; experience with Phoenix, Elixir, Python, Erlang, JavaScript.
• Ability to work in a fast-paced, collaborative team.
• Exceptional problem-solving skills with a track record of tackling tough engineering challenges.
• Curiosity and growth mindset; comfortable with novel challenges using fundamentals.
• Familiarity with open-source tech and willingness to experiment.
• Experience building 0-1 products with strong product sense.
• Excellent communication and ability to articulate technical decisions.
• Passion for healthcare software is a plus.

Responsibilities

• Tackle modern cloud architecture and design a scalable platform core with Elixir.
• Develop a robust access control system for clinical data.
• Ensure 24/7 hospital uptime with reliable deployments and data sync.
• Bridge the gap between software and hardware with real-time integration.

Skills

Software engineering

OO & functional programming

Problem solving

Growth mindset

Open-source familiarity

Product sense

Tools

Phoenix

Elixir

Python

Erlang

JavaScript

Job description

About Us:

Lunar is a stealth technology company building a new type of software platform for health systems. We are on a mission to revolutionize healthcare with cutting-edge, AI-powered software designed to help every hospital deliver world-class care for their patients. Our platform is already the core backbone of health systems today, transforming clinical and operational workflows at scale with the world’s first AI-native hospital information system.

This next-generation platform is a fundamental rebuild of the information infrastructure that runs health systems. All of it – from doctors, nurses, pharmacists, lab technicians, coders, billers, supply chain, and even patients – Lunar’s software powers everything, soup-to-nuts. We believe that this mission is the moon landing of healthcare – something so consequential and ambitious that most people believe it to be impossible.

Backed by Silicon Valley’s preeminent venture capital firms, we believe in the power of a high performance team of seasoned professionals operating at the peak of their abilities. We value people who are driven, curious, have sound judgement, and care about doing the best work of their careers.

We run hospitals on Elixir. We’ve embraced Elixir for its fault tolerance, concurrency, and scalability - essential for handling real-time patient data in mission-critical settings like Emergency Departments, ICUs, and Operating Rooms.

We are looking for a Senior Product Engineer who’s excited to tackle some of the hardest technical problems in healthcare - and do it with a fast-moving, and deeply mission-driven team. If you care about writing clean, robust code and want to rebuild from scratch the software infrastructure of modern hospitals, we’d love to talk.

Here are some deep technical problems you may tackle in your first 6 months:

• Modern cloud architecture, built from scratch: We have no legacy systems to untangle. We’re designing a modern cloud-native platform with Elixir at its core.

• Develop a radically better access control system for clinical data: Create a modern access control system with fine-grained permissions that respects clinical data structure and patient data ownership, while enabling population-level insights for better public health.

• Keep hospitals online 24/7 - no matter what: Design and ship infrastructure that can handle rolling deployments, failover, and real-time data sync in environments where downtime isn’t an inconvenience - it’s a risk to patient care.

• Bridge the gap between software and hardware: Architect a next-generation integration engine to connect ventilators, bedside monitors, imaging equipment, lab equipment, and more - reliably and in real time.

• Push hospital workflows into the modern age: Rethink and rewire how data moves between nurses, doctors, and administrators - and turn confusing, click-heavy workflows into fast, intuitive experiences.

Your Experience:

• Minimum of 10 years of professional software engineering experience.

• Proficiency with object oriented and functional programming, with the ability and willingness to use and adopt new technologies. We use tools such as Phoenix, Elixir, Python, Erlang, Javascript, and more.

• Strong ability to work in a fast-paced, collaborative, and innovative team environment.

• Exceptional problem-solving skills, with a track record of tackling challenging engineering problems.

• Intellectually curious with a growth mindset - able to tackle entirely novel challenges that lack prior precedent through applying strong fundamentals and first principles thinking.

• Familiarity with open-source technology and a desire to explore and experiment with new solutions.

• Experience building 0-1 with a strong product sense.

• Excellent communication skills and the ability to articulate technical decisions, trade-offs, and best practices.

• A passion for making a meaningful impact in the healthcare industry through software innovation is a plus.

Hospitals are some of the most complex, under-served environments in all of tech. We’re bringing the best of modern software practices to an industry that’s been left behind - and building tools that clinicians love, not tolerate.

If you’re an engineer who wants to work on meaningful problems with real-world impact, this is your chance.

At Lunar, we know our greatest strength is the diverse blend of backgrounds, experiences, and ideas that our team members contribute. We’re passionate about healthcare, but we are also passionate about creating an inclusive workplace where every unique talent and perspective is not just respected, but celebrated. We thrive on embracing differences and are fully committed to fostering a fair, supportive, and dynamic environment where everyone has the opportunity to shine. All applicants will be considered for employment regardless of race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.