Mobile frontend engineering

Lucis; Paris; On-site; EUR 70,000 - 110,000; Full time

Benefits offered by this job

Relocation support

AI-powered development

Paris hub-based team

Job summary

Lucis is seeking a senior mobile frontend engineer to own the app end-to-end from our Paris hub. You will craft delightful, performant experiences with Expo and React Native, shaping interactions, motion, and overall feel while leveraging a modern monorepo and AI-enabled workflows.

You’ll review AI-generated code, write precise specs, and drive decisions that improve the product for users seeking proactive health insights. Relocation support is available for the right candidate in Paris.

Qualifications

• 8+ years of confirmed mobile engineering experience.
• Proficient with Expo and React Native; comfortable with native experience.
• Strong sense for design, interactions, motion and details.
• Ability to write specs before coding to guide AI agents.

Responsibilities

• Own the mobile experience end-to-end in our monorepo.
• Think in interactions, motion, and detail to ship delightful UI.
• Review AI-generated code with a critical eye for quality and security.
• Collaborate across teams to push fast, reliable releases.

Skills

Mobile frontend engineering

Design-driven development

End-to-end ownership

Tools

Expo

React Native

NestJS

PostgreSQL

Prisma

AWS

Terraform

Qovery

GitHub Actions

Claude Code

Cursor

Job description

Making preventive health the default for every human in Europe

The mission

At Lucis, we believe healthcare should be preventive, not reactive. We’re building the OS for human longevity to help people add more healthy years to their lives. You can read more about who we are and how we work here.

The role

We’ve processed 200,000+ clinical tests across 4 countries with a team of 20. We’re growing 10% week over week. And we’re still early.

We’re looking for a mobile frontend engineer who treats the app as a craft, not a checklist. You care about the half-pixel, the spring curve on a transition, the way a screen feels in the hand, and you can build it. You own the mobile experience end-to-end in our monorepo, orchestrate AI to execute, and raise the bar for everyone around you.

You won’t spend your days writing boilerplate. You’ll write specs that agents execute, review AI-generated code with a critical eye, and make decisions that compound over time. This is what engineering looks like now. If that excites you, keep reading.

What we’re looking for: Mobile frontend, design engineering & world-class craft

A confirmed mobile engineer (8+ years) with exceptional craft and a real sensibility for design. You live in Expo and React Native, you care deeply about how the product feels, and you don’t wait for designs to be ready to propose something delightful. You have also experience building native experience. You think in interactions, motion, and detail.

You’ll own what members touch every day: onboarding, the core app surfaces, the moments that turn a first‑time visitor into someone who trusts us with their health. Your work has to be delightful and reliable on real devices, for people who decide in minutes whether to trust us.

About you

You’re passionate about the future of human health and want your work to help people stay healthy for longer. You move quickly from idea to execution, take full ownership of what you build, and work best with talented people who care as much as you do.

You thrive in fast‑moving environments, learn by doing, and value feedback as a way to continuously improve. You use AI the way others use a calculator: naturally, to go faster and think bigger.

You’ll fit in well if

• You've shipped at least one product from 01 and felt the difference between writing code and building a system

• You have 2 deep areas of expertise and can operate across the full stack when the situation demands it

• You write specs before you write code — precise enough that an AI agent executes correctly on the first pass

• You review AI-generated code with the same rigor you'd apply to a junior engineer's PR: edge cases, security gaps, design smell

• You bias toward shipping. A good decision today beats a perfect one next week

• You're genuinely interested in health — maybe you track your own biomarkers, or you're just frustrated that healthcare is still reactive

We would not be a fit if

• You need a clearly scoped role before you can operate

• You measure output in lines of code written

• You've only worked in large orgs with dedicated infra, QA, and platform teams

• You optimize for stability over velocity

Our current stack

TypeScript monorepo · React Native · NestJS · PostgreSQL + Prisma · AWS (Terraform, Qovery) · GitHub Actions · Claude Code + Cursor

The process

• Intro call (20 min): culture & role fit.

• Technical interview (30 min)

• At-home case study: hands-on project, delivery in 2 days.

• Deep dive (90 min) and team chat (on-site)

• Reference calls

How we work

We work together from our Paris hub. We’re passionate about what we’re building and believe the fastest way to create something exceptional is side by side. We’re open to relocation support for the right individuals, and we welcome missionaries who travel to work with us in Paris on a regular basis.

• Rigor without ego: Audits, science, and code all deserve the same high bar.

• Radical ownership: Feedback loops are short; everyone contributes to building the best version of Lucis.

• Velocity over perfection: We ship daily and prefer a good decision today over a perfect one next week.

At Lucis, AI isn't just our product, it's our engine. 100% of our teams are equipped with the best AI agents. You have carte blanche to explore and automate everything that can be, so you can focus exclusively on high-value work.