Frontend Engineer (JavaScript / React)

As a Front End Developer, you will be responsible for designing, developing, and maintaining the client-side components, user interfaces, and user experience of our software applications. This role requires deep expertise in front-end technologies and the ability to build performant, accessible, and scalable user interfaces while collaborating effectively within an agile team environment.

You will work closely with Engineering Managers, Product Managers, Back End Developers, Designers, and other team members to implement features, improve application architecture, and ensure high-quality deliverables that meet both technical and business requirements. Curious by nature, you won’t hesitate to dive into back-end tasks when the context calls for it, bringing a full-stack mindset to the problems you tackle.

You will be part of a cross-functional squad and will contribute to technical decisions while maintaining high standards of code quality, performance, accessibility, and user experience.

Learn more about our Tech Team through our Medium

Key responsibilities:

Technical Development

• You will design, develop, and maintain scalable React applications and reusable component libraries

• You will build responsive and accessible user interfaces following design systems and UI/UX best practices

• You will write clean, maintainable, and well-tested code following team standards and best practices

• You will participate in code reviews and provide constructive feedback to team members

• You will debug production issues and implement robust solutions

• You will contribute to technical documentation and architecture decisions

• You will integrate RESTful APIs endpoints into the front-end application

• You will optimize application performance, bundle size, and loading times

• You will implement state management solutions and client-side caching strategies

• You will participate in agile ceremonies and technical planning sessions

Collaboration and Innovation

• You will actively participate within an autonomous mission team (PM, Designer, Engineering manager, Back End Developers) to clarify priorities and user needs

• You will contribute to technical discussions and architecture decisions

• You will collaborate with designers to implement pixel-perfect, accessible interfaces

• You will work with back-end developers to define API contracts and data structures

• You will participate in squad rituals and team meetings

• You will handle support requests and bug fixes within agreed SLAs

Quality & Best Practices

• You will write unit tests, integration tests, and end-to-end tests following TDD principles

• You will collaborate with QA team to ensure comprehensive test coverage

• You will participate in pair programming sessions with team members

• You will monitor application performance, Core Web Vitals, and implement improvements

• You will follow accessibility standards (WCAG) and ensure inclusive user experiences

• You will contribute to continuous integration and deployment processes

• You will implement error tracking, monitoring, and analytics

• You will ensure cross-browser compatibility and responsive design

• You will optimize for performance: code splitting, lazy loading, image optimization

You’d be our ideal candidate if you:Experience & Expertise3 to 5 years of professional front-end development experienceStrong expertise in modern web application architecture and React ecosystemTechnical SkillsProficient in JavaScript/TypeScript, React (Hooks, Context, Router), and modern ES6+ featuresExperienced with state management (Redux, Zustand, TanStack Query) and API integration (REST)Skilled in CSS (Modules, Styled Components, Tailwind), build tools (Webpack, Vite), and testing (Jest, React Testing Library, Playwright, Cypress)Knowledgeable in performance optimization, accessibility standards (WCAG, ARIA), responsive design, and design systems (Storybook)Comfortable with Git, CI/CD practices, and modern development workflowsSoft SkillsExcellent problem-solving abilities with strong attention to detailFluent in both French and EnglishCollaborative team player with product thinking and user-centric mindsetProactive in suggesting improvements with a focus on maintainable, well-documented codePassionate about user experience, accessibility, and inclusive design

Welcome to the Jungle aspires to have a positive social impact, and pays particular attention to respecting diversity, inclusion and equity. Regardless of qualifications, we’re looking for a passionate individual who will fit in well with the team and take responsibility for these issues.