Senior Frontend Engineer (React)

N-iX
Municipality of Madrid, Spain
2 days ago

Role details

Contract type
Permanent contract
Employment type
Full-time (> 32 hours)
Working hours
Shift work
Languages
English
Experience level
Senior

Job location

Remote
Municipality of Madrid, Spain

Tech stack

JavaScript
Amazon Web Services (AWS)
HTML5
Automation of Tests
CSS
Software Quality
Code Review
DevOps
Performance Tuning
Blockchain
Next.js
Responsive Web Design
Software Engineering
TypeScript
Web Performance Optimization
Web Usability
React
Delivery Pipeline
Caching
Backend
GIT
Information Technology
GraphQL
Front End Software Development
REST

Job description

The Senior Software Engineer, Web is part of the Engineering team and reports to our Manager, Engineering. As a Senior Software Engineer, Web, you will be responsible for designing and building scalable, high-performance web applications using Next.js and modern front-end technologies.

You will partner with Product, Design, Backend, and DevOps teams to deliver performant, accessible, and secure user experiences while contributing to front-end architecture and engineering best practices.

Working hours 12:00 - 20:00 CET., * Design and implement scalable front-end features using Next.js, React, and TypeScript.

  • Own end-to-end development of web features, including testing, deployment, and maintenance.
  • Build modular and reusable UI components to support scalable development.
  • Optimize web performance through SSR/SSG, lazy loading, and responsive design techniques.
  • Monitor and improve performance metrics such as page load time, TTI, and Core Web Vitals.
  • Collaborate cross-functionally with Product, Design, Backend, and DevOps teams to define requirements and deliver features.
  • Contribute to front-end architecture decisions and engineering best practices.
  • Participate in code reviews and mentor junior engineers to improve code quality and team standards.
  • Partner with DevOps to support CI/CD pipelines and reliable deployment processes.
  • Ensure high standards in code quality, accessibility, security, and automated testing (unit, integration, E2E).

Requirements

Do you have experience in UI?, Do you have a Master's degree?, * Bachelor's or Master's degree in Computer Science or related field.

  • ~8 years of professional software engineering experience, or ~6 with an advanced degree.
  • Strong communication and collaboration skills, motivation, problem solving mind set.
  • Strong proficiency in Next.js, React, TypeScript, JavaScript, HTML5, and CSS3.
  • Strong experience with GraphQL and REST API.
  • Experience with performance optimization tools (Lighthouse, WebPageTest, Chrome DevTools).
  • Solid understanding of SSR/SSG, CDN strategies, caching, and responsive design principles.
  • Familiarity with front-end security best practices.
  • Experience with Git, CI/CD pipelines, and modern deployment workflows.
  • Exposure to cloud platforms such as AWS or GCP.
  • Strong collaboration skills working with Product, Design, and Backend teams.
  • Experience mentoring junior engineers and contributing to team development.
  • Bonus: Experience with analytics instrumentation or blockchain-integrated front-ends (e.g.,ethers.js, wallet integrations).

Benefits & conditions

  • Flexible working format - remote, office-based or flexible

  • A competitive salary and good compensation package

  • Personalized career growth

  • Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)

  • Active tech communities with regular knowledge sharing

  • Education reimbursement

  • Memorable anniversary presents

  • Corporate events and team buildings

  • Other location-specific benefits

  • not applicable for freelancers

About the company

Our client is a leading, fully regulated US-based digital asset trading platform. They provide secure, low-latency access to cryptocurrency markets, acting as a bridge between traditional finance and the Web3 ecosystem.

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