Lunar Client Jobs in California (NOW HIRING)

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 build rich, reactive interfaces in TypeScript and React, talking to our backend over GraphQL - where the UI updates the instant the underlying clinical data changes. On the backend, 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 Staff Frontend Engineer who's excited to tackle some of the hardest interface and interaction problems in healthcare - and do it with a small, fast-moving, and deeply mission-driven team. If you care about crafting clean, robust, intuitive interfaces and want to rebuild from scratch the software that clinicians rely on every day, we'd love to talk.

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

• Build a clinical design system from scratch: Design and ship a component library and design system that brings consistency, speed, and polish to every screen a clinician touches.

• Push hospital workflows into the modern age: Rethink and rewire how clinicians move through the software - and turn confusing, click-heavy workflows into fast, keyboard-driven, intuitive experiences that clinicians love, not tolerate.

• Render real-time clinical data, instantly: Build interfaces that reflect live patient data - vitals, orders, labs, alerts - the moment it changes, with no lag, in environments like the ED, ICU, and OR where a half-second matters. Architect the data layer, caching, and subscription patterns over GraphQL that make that possible.

• Make interfaces that never fail under pressure: Engineer for accessibility, resilience, and performance so the UI holds up in high-stakes, high-stress settings - including degraded networks and edge cases that would break an ordinary web app.

• Turn complexity into clarity: Take dense clinical and operational data and shape it into clear, glanceable, decision-ready interfaces for doctors, nurses, pharmacists, and administrators.

• Define the frontend from first principles: Set the patterns, state management, and rendering architecture - balancing developer velocity against the reliability bar of mission-critical software.

Your Experience: 

• Minimum of 10 years of professional software engineering experience, with deep focus on frontend.

• Expertise across the frontend stack including TypeScript, JavaScript, React, HTML, CSS, browser internals, rendering performance, state management and building real-time, reactive UIs against GraphQL APIs

• Comfortable adopting new tools as needed (we use Elixir/Erlang, Phoenix, Postgres and AWS in the backend).

• Experience with client-side data loading and management: caching, freshness, ownership, and how to optimize push updates

• Understanding of the browser rendering cycle, how and when the DOM decides what to repaint, and the instinct to profile and optimize for a responsive, data-dense interface.

• Well-versed in modern React patterns and functional programming principles, including advanced use of custom hooks to build performant, maintainable, and reusable component architectures at scale.

• Deep fluency with async control flow in JavaScript (Promises, async/await) and a track record of diagnosing race conditions, ordering issues, and unhandled rejections in real-time systems.

• 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 novel challenges 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.

Compensation Range: $190K - $250K