Senior Frontend Engineer (React)

Zartis

Location: Europe
Job Type: full-time
Salary: Unknown
Posted: August 29, 2025

Job Description

The company and our mission:

Zartis is a digital solutions provider working across technology strategy, software engineering, and product development.

We partner with firms across financial services, MedTech, media, logistics technology, renewable energy, EdTech, e-commerce, and more. Our engineering hubs in EMEA and LATAM are full of talented professionals delivering business success and digital improvement across application development, software architecture, CI/CD, business intelligence, QA automation, and new technology integrations.

We are looking for a Senior Frontend Engineer to work on a project in the fintech industry.

The project:

Our teammates are talented people that come from a variety of backgrounds. We’re committed to building an inclusive culture based on trust and innovation.

You will be part of a distributed team developing new technologies to solve real business problems. A React Developer builds and maintains dynamic, responsive user interfaces using the React.js library. This role involves developing reusable components, managing application state, and integrating front-end features with backend systems to deliver seamless and performant web experiences.

We are looking for someone with good communication skills, ideally with experience making decisions, being proactive, and with good attention to detail.

What you will do:

- Develop and maintain scalable, reusable front-end components using React

- Translate UI/UX designs into responsive, interactive web interfaces

- Manage application state using tools like Redux and Context API

- Integrate front-end components with backend APIs

- Optimize application performance, load times, and responsiveness

- Ensure cross-browser compatibility and accessibility standards

- Write clean, well-documented, and maintainable code

- Participate in code reviews, testing, and debugging

- Contribute to creating SDKs for internal and public use

What you will bring:

- You’re a front-end developer with strong hands-on experience in React, passionate about building fast, accessible, and user-focused web applications.

- You have a proven ability to turn UI/UX designs into responsive, maintainable interfaces and work effectively as part of a collaborative engineering team.

- Solid experience with React.js and modern JavaScript (ES6+), with a strong grasp of component-based architecture and hooks.

- Experience managing application state using Redux, Context API

- Familiarity with integrating APIs (REST) and handling asynchronous data flows.

- Ability to write clean, reusable, and well-documented code, with a focus on performance and scalability

- Strong understanding of responsive design, browser compatibility, and accessibility standards

- Experience with version control systems like Git and working in agile development environments

- Comfort with participating in code reviews, testing, and debugging in a team-based setting

- Familiarity with creating SDKs or reusable packages is a plus

- A collaborative mindset and clear communication skills, with a willingness to learn and contribute to team success

What we offer:

- 100% Remote Work

- WFH allowance: Monthly payment as financial support for remote working.

- Career Growth: We have established a career development program accessible for all employees with a 360º feedback that will help us to guide you in your career progression.

- Training: For Tech training at Zartis, you have time allocated during the week at your disposal. You can request from a variety of options, such as online courses (from Pluralsight and Educative.io, for example), English classes, books, conferences, and events.

- Mentoring Program: You can become a mentor in Zartis, or you can receive mentorship, or both.

- Zartis Wellbeing Hub (Kara Connect): A platform that provides sessions with a range of specialists, including mental health professionals, nutritionists, physiotherapists, fitness coaches, and webinars with such professionals as well.

- Multicultural working environment: We organize tech events, webinars, parties, and activities to do online team-building games and contests.

🎯 Who is this job for?

Zartis is hiring a Senior Frontend Engineer (React) based in the European Union to join a fintech project, focusing on building fast, accessible, and user-centric web applications. The role involves developing reusable React components, translating UI/UX designs into responsive interfaces, managing state (Redux, Context API), integrating with REST APIs, optimizing performance, and ensuring accessibility and cross-browser compatibility. Candidates should bring strong React/JavaScript (ES6+) expertise, hooks, component-based architecture, Git, agile experience, and collaborative communication skills, with bonus points for SDK or reusable package development. Zartis offers 100% remote work, monthly WFH allowance, structured career growth with 360º feedback, dedicated training time (courses, conferences, English classes), mentoring opportunities, wellbeing programs, and a multicultural team culture.

💬 Potential Interview Questions

How many years of experience do you have working with React and modern JavaScript?
I have over 6 years of experience working with React and modern JavaScript (ES6+), building scalable, component-based applications and delivering responsive, performant user interfaces.
What is your approach to translating UI/UX designs into code?
I collaborate closely with designers to ensure accurate implementation, focusing on responsiveness, accessibility, and maintaining pixel-perfect detail while optimizing for performance.
How do you manage application state in React applications?
I use Redux and Context API for predictable and scalable state management, ensuring clean architecture and smooth handling of asynchronous data flows.
What experience do you have with API integration?
I have integrated REST APIs in multiple projects, handling asynchronous data with tools like Axios and Fetch while ensuring proper error handling and performance optimization.
How do you ensure performance and scalability in your frontend applications?
I apply techniques such as code-splitting, memoization, lazy loading, and performance profiling, along with writing clean, reusable components to optimize load times and scalability.
What is your experience with accessibility and cross-browser compatibility?
I ensure all applications meet accessibility standards (WCAG), implement semantic HTML, test across multiple browsers, and include responsive design for a wide range of devices.
How do you maintain code quality within your team?
I participate actively in code reviews, follow clean code practices, write reusable components, and ensure thorough testing and documentation to maintain a high standard of quality.
Do you have experience creating SDKs or reusable packages?
Yes, I have experience contributing to shared libraries and reusable packages, ensuring consistency, maintainability, and scalability across projects.
How do you collaborate in a distributed, remote-first team?
I maintain clear communication, document thoroughly, use Git for version control, and participate actively in Agile ceremonies to stay aligned with cross-functional teams.
Why are you interested in joining Zartis?
I admire Zartis’s focus on innovation, mentorship, and career growth, and I am motivated by the opportunity to contribute to impactful fintech solutions while working in a diverse, global environment.

📋 Job Summary

Zartis is a global digital solutions provider specializing in technology strategy, software engineering, and product development. With engineering hubs across EMEA and LATAM, the company partners with clients in industries such as fintech, MedTech, renewable energy, e-commerce, and logistics to deliver scalable applications, modern architectures, and innovative technology integrations. Focused on building inclusive, collaborative teams, Zartis fosters growth through structured career development, mentorship, continuous training, and well-being initiatives, while offering a fully remote and multicultural work environment.