Front-End Developer Senior (H/F)

About Zelty

Zelty is the super-app for restaurants for checkout, order taking, and business management, on a daily basis.
Zelty offers an innovative iOS solution (Cash Register, Multi-site BO, Click&Collect, Delivery...) that is modular and open (+85 integrations) which allows restaurateurs to go digital, in order to focus on their concepts and their customers.
Launched in 2015, Zelty's checkout solution is today the leader in multi-site restaurant management in France. And it's not over yet!
Zelty is committed to equality of opportunity and offers an inclusive work environment where every person is respected and valued, regardless of their gender, sexual orientation, age, origin, religion, or disability status.
Job Description

In a context of product and technical maturity, we are strengthening the Tech team with a

Front-End Developer Senior

capable of elevating our standards of architecture, quality, and performance.
At Zelty, our interfaces are used every day by thousands of restaurateurs, often in critical moments.
The front end is not "just an interface": it is

their daily work tool .
Every millisecond counts, every interaction must be reliable.
Your role:

build a robust, scalable, and high-performance front-end , while structuring the team's technical practices.
Here, you don't just develop: you lay down lasting foundations and contribute directly to the quality of the product.
Your Mission and Impact

You will contribute to the strength and evolution of Zelty's front-end through

four major axes :
Architecture & Front Structuring (35%)
Design and structure complex applications in React / TypeScript

Implement clear and long-lasting architecture patterns (MVVM notably)

Define and evolve code standards

Ensure the long-term maintainability of the front-end foundation

You are a

technical reference

on architecture topics
You build a readable, robust, and scalable front-end
Quality, Performance & Technical Excellence (30%)
Ensure overall quality (readability, testability, performance, accessibility)

Structure a solid testing strategy (unit, integration, e2e)

Optimize performance (runtime, build, UX in real conditions)

Manage technical debt with pragmatism

You are demanding on code, but always focused on impact
You seek to simplify, improve, and make reliable continuously
Design System & Product Coherence (20%)
Contribute actively to the design system and its evolution

Maintain an industrialized UI Kit (Storybook, documentation, governance)

Collaborate closely with Product & Design

You participate in a fluid, coherent, and reliable experience for users
Collaboration & Collective Impact (15%)
Participate actively in code reviews (in a logic of sharing and progress)

Be a force of proposal on tools, processes, and best practices

Challenge technical choices with benevolence and pragmatism

Collaborate with Back-End, Product, and Design

You contribute as much to the quality of the code as to

the team's dynamic
You like to make others progress as much as yourself
Profile Sought

Hard Skills

Solid experience in

React

and

TypeScript

on complex applications

Concrete experience in front-end architecture (MVVM or equivalent)

Good mastery of

Next.js

(SSR, performance, rendering)

Very good understanding of front-end performance issues

Experience on a structured design system (Storybook, UI Kit…)

Practice of tests, CI/CD, and quality best practices

You are comfortable moving from the global vision to implementation
Technical Stack
Framework:

React, Next.js

Build & Bundling:

Vite, Rollup

Language:

TypeScript

State Management:

MobX, Redux, Zustand

Server State & Cache:

React Query

Forms & Validation:

React Hook Form, Yup

Styling:

Styled Components, SASS

Internationalisation:

i18next

Monitoring & Analytics:

Sentry, Amplitude, LaunchDarkly

Testing:

Vitest, Playwright

Cloud & Infrastructure:

AWS Lambda, AWS S3, AWS Amplify

CI/CD:

Semantic Release, GitHub Actions

Soft Skills (Very Important to Us)

We are looking for a profile:
Technically demanding , with a real sensitivity to architecture & quality
Pragmatic : you know how to make the right choices without falling into dogmatism
Curious and committed : you want to make the product and the team progress
Team player : you like to share, challenge, and build together
Positive and enthusiastic : you bring a good energy to the team
Responsible : you take ownership of your scope
You want to have a real impact, not just execute tasks
You are looking for a role where you can:
influence the architecture
improve the product quality sustainably
work with a committed and demanding team
This role is for you.
At Zelty, we value the diversity of backgrounds and experiences. No profile corresponds perfectly to a job description: if you recognize yourself in the spirit of the role and in our values, do not hesitate to apply.

Recruitment Process

1⃣ A first exchange with Elsa, Talent Recruiter (30 min, via video)
2⃣ Manager interview with Steven, Tech Lead (1h, via video)
3⃣ Technical test and debrief with Steven and Vincent, our CEO / VP Engineering (1h30, in person)
4⃣ Culture Fit interview with Thomas (Head of Product) and Marc (CTO) and Team Tech and Product meeting (in person)
Welcome
At each stage, we commit to giving you a clear and quick feedback.
See you soon
Additional Information

Type of contract:
Location:
Level of