Senior Front-End Engineer

$230,000 - $280,000
Full-time / Onsite (5 days/week)

About The Role

At Mochi, our engineering team operates with exceptional leverage. We believe in high talent density, where a focused, elite team powers a profitable, nine-figure ARR healthcare platform serving hundreds of thousands of patients. We are looking for a Senior Frontend Engineer to own the interfaces that our patients and medical providers rely on every single day.

Mochi has already helped patients lose over 5 million pounds through metabolic care, and we are now rapidly expanding into the frontiers of preventative healthcare—including hormone optimization (HRT/TRT), longevity medicine, and cutting-edge peptide therapies. As a frontend leader, you will dictate how this next wave of patients discovers treatments, interacts with their care team, and safely tracks their health outcomes.

Because of our high scale-to-team ratio, we do not operate in isolated technical silos, and we do not throw requirements over the wall. You will own your applications end-to-end: architecting the client-side state, building flawlessly responsive UI, optimizing rendering performance, and owning the frontend observability in production. If you are drawn to product problems where the UX complexity is real, the autonomy is absolute, and the impact on patient outcomes is tangible, this is the role.

What You’ll Do

• Build High-Density Healthcare Interfaces: You will build the complex tools our clinical team relies on to treat patients safely. You will architect dynamic, multi-step medical intake engines, high-density provider charting dashboards, and patient-facing applications that handle sensitive PHI with perfect state synchronization.
• Master Client-Side Architecture: Healthcare data is heavy and highly relational. You will design robust, scalable frontend architectures that manage complex state, handle asynchronous data fetching cleanly, and ensure interfaces feel instantaneous even when underlying APIs are slow.
• Collaborate Across the Client Ecosystem: While your primary domain is the web, Mochi also heavily leverages React Native and Expo for our mobile applications. You will work closely with mobile engineers to establish shared state patterns, reusable business logic, and a unified architectural standard across all client platforms.
• Champion the User Experience: You don't just implement specifications; you deeply care about how patients and providers experience Mochi. You sweat the details of the UI and possess the strong product sense required to make pragmatic, high-quality design decisions on the fly using our component systems that measurably improve patient outcomes.
• Own Frontend Reliability: You are responsible for what happens after the code ships. You will own the frontend deployment pipelines, establish strict performance budgets, and manage client-side observability and error tracking (e.g., Sentry, Datadog) to catch regressions before our patients do.
• Build Agentic Workflows: Mochi is an AI-first engineering org. You will not only utilize frontier agentic models to accelerate your own development, but you will also integrate AI capabilities directly into our product interfaces to automate clinical operations and scale our provider workflows.

Who You Are

• You have operated high-stakes systems. You have 5-7+ years of frontend engineering experience. You've built and operated production React applications that handle real complexity, crossing the boundary between dense data visualization and polished, accessible user experiences.
• You master React and state architecture fundamentals. You understand the React render cycle deeply, moving beyond surface-level hooks to truly orchestrate complex data flows. You know the tradeoffs between server-side rendering, static generation, and client-side fetching, and you leverage tools like Next.js pragmatically without over-complicating the architecture.
• You are an independent product builder. You don't need a pixel-perfect Figma file to ship great software. You have a strong eye for design and can unblock yourself visually while maintaining strict adherence to our design system and brand language.
• Your workflows are altered by AI. You are already using frontier agentic tools (e.g., Codex 5.3, Claude Opus 4.6) to build faster. You can describe specific ways these models have structurally changed how you code, while retaining the deep technical skepticism required to audit, verify, and own its output.
• You are a collaborative builder. You have low ego, high standards, and excellent communication skills. You thrive in cross-functional environments where engineering requirements are heavily shaped by healthcare regulations, compliance, and patient safety.
• You are excited to work in-person. You want to build alongside the team 5 days a week in our San Francisco office.
• If you are targeting Staff leveling: We expect a demonstrated track record of setting technical direction across teams, navigating deep ambiguity, and measurably leveling up the engineers around you.
• Our frontend stack is TypeScript, React, Next.js, Tailwind CSS, and modern state management/data fetching tools (e.g., React Query, Zustand). Experience with these is a strong plus, but we index on engineering fundamentals, web performance, and product sense over framework dogmatism.

Our Process

We respect your time. Here is exactly what to expect:

• Intro call (30 min, remote) — Chat with our recruiter about the role and expectations.
• Hiring manager screen (45 min, remote) — Technical background, motivation, and what you're looking for.
• Technical round (2.5 hrs, remote) — Practical coding (AI tools welcome) + system design conversation. Real problems, not LeetCode.
• Team meet (2 hrs 15 mins, on-site) — Come to our SF office to meet your future manager, engineering peers, and product partners for 30-minute 1:1s, concluding with a quick recruiter wrap-up.
• We are ready to move as fast as you are. Total interview time is ~6 hours. We can go from the first intro to offer in two weeks, or pace the rounds to comfortably fit your current work schedule.

Our Core Technologies Include: Typescript, Javascript, Node.js, Next.js, React, React Native, SQL, Redis, Redux, New Relic, Kubernetes, CSS, AWS, Cypress, Docker, Express

Life at Mochi 

At Mochi, we believe your best work happens when you feel your best—so we’ve designed an environment that fuels your creativity, supports your growth, and makes every day exciting.

🥗 Daily Meals and Espresso Bar - Breakfast, lunch, and dinner every weekday. Our on-site barista keeps the espresso and matcha flowing all day

💰 Pre-Tax Commuter Perks - Save on transit and parking through pre-tax commuter benefits

💸 Top-of-Market Compensation - We offer competitive salaries along with generous equity packages so you can share in the success you help create

💣 Profitable and Rapid Growth - We’re scaling fast, with financial discipline and long-term vision. No VC constraints, just sustainable momentum and smart decisions

🚀 High-Impact Work - Help shape the future of digital healthcare. Your work here directly improves lives and scales nationwide

👩‍💻 World-Class Team - Collaborate with teammates from Tesla, SpaceX, Citadel, Harvard, IIT, and more. We value excellence, humility, and empathy in equal measure

✨ Comprehensive Benefits - 401(k) with match, generous time off, life insurance, and high-quality medical, dental, and vision plans

💊 Mochi Health Membership – We cover your monthly subscription fee so you can experience the same care as our patients (medications not included)

🌴 Time to Recharge –Enjoy unlimited PTO, generous company holidays, and true flexibility. We trust you to take the time you need to rest, reset, and thrive

🧘 Wellness First –From weekly mindfulness sessions to group workouts and fitness perks, your physical and mental health are top priority

🎉 Team Socials and Community - We make time to connect through regular socials, happy hours, and spontaneous events. Our stocked kitchen doesn’t hurt either

📍 Downtown SF HQ - Our San Francisco office is just steps from BART, Muni, and great food. It’s designed for deep work and casual collaboration

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The base salary for this full-time position ranges from $230,000 to $280,000, in addition to equity and benefits. The salary range listed in each job posting represents the minimum and maximum targets for new hire salaries across all locations. Actual compensation within this range is determined by various factors, such as job-related skills, experience, relevant education or training, and location.

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