N-ix

Senior Frontend Engineer (React)

Poland; Portugal; Romania; Spain Full Time

Company Overview

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.

About This Role

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.

Key Responsibilities

  • 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).

Required Qualifications

  • 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).

We offer*:

  • 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