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La Fosse

Frontend Developer

La Fosse
Spain · Full-time · Mid-Senior

Job Title: Senior Frontend Developer

Location: Fully Remote

Rate: €300–€350 per day (depending on experience)

Contract: Open-ended


Overview

We are looking for a Senior Frontend Developer to play a key role in building and evolving high-performance web applications. You will be responsible for developing modern, conversion-focused user interfaces, contributing to frontend architecture, and driving performance improvements across a range of digital products.


You will work closely with Product, Design, Marketing, QA, and Backend teams to deliver scalable, user-centric solutions.


Key Responsibilities

• Build modern, high-conversion user interfaces using React and Next.js

• Develop and maintain frontend architecture with a modular and scalable approach

• Implement new features from scratch while improving and optimising existing applications

• Develop frontend components for both public-facing products and internal tools

• Ensure cross-browser and cross-device compatibility

• Write clean, reusable, and maintainable TypeScript code

• Integrate with REST and/or GraphQL APIs and manage asynchronous data flows

• Participate in code reviews and contribute to engineering best practices

• Continuously identify opportunities to improve performance, scalability, and user experience

• Collaborate closely with cross-functional teams across Product, Design, Marketing, and QA


Requirements

• Strong experience with React and Next.js

• Solid experience using TypeScript in production environments

• Strong understanding of modern JavaScript, including asynchronous programming (Fetch API, Axios)

• Experience consuming RESTful APIs and/or GraphQL services

• Good understanding of frontend architecture, modular design, and design patterns (SOLID principles)

• Experience with NPM and package management, including optimisation

• Familiarity with testing frameworks and writing testable code

• Working knowledge of AWS and cloud-based deployment practices

• Strong understanding of JSON and API data handling, including error management

• Comfortable working in cross-functional teams in an agile environment


Nice to Have

• Experience with performance optimisation and frontend monitoring

• Familiarity with AI-assisted development tools and workflows

• Previous experience working on high-traffic or conversion-focused platforms


Soft Skills

• Strong problem-solving ability and attention to detail

• Proactive mindset with a high level of ownership

• Clear communicator, comfortable working with both technical and non-technical stakeholders


Additional Requirement

• Native or fluent Spanish (written and spoken) is mandatory

Key Skills

Ranked by relevance

product design typescript graphql react design patterns restful apis javascript cloud aws npm ai
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Posted
Apr 08, 2026
Type
Full-time
Level
Mid-Senior
Location
Spain
Company
La Fosse

Industries

Software Development

Categories

Engineering

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