Senior Frontend Developer (React)

Gravity 9

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

Job Description

We are excited to share that our company is experiencing significant growth and expansion, and as a result, we're on the lookout for talented individuals to join our team.

We want to be upfront about our hiring process. At this moment, we are in the process of securing projects that align with our business goals and objectives. Our intention is to ensure that once we bring new team members on board, they will have a meaningful and impactful role to play from day one. While we might not be able to extend an offer immediately, we are highly interested in considering you for these future projects.

If you're open to the idea of potentially joining our team in the future, we encourage you to continue with our interview process. We value your time and effort and believe that getting to know you better will help us make an informed decision.

Once you have effectively concluded the entire recruitment procedure, we will retain your profile and reach out to you once a suitable opportunity emerges. Additional interviews will not be necessary at this stage, and we anticipate being able to extend an offer to you promptly.

What does the recruitment process look like?

1. Recruiter Screen

In the first call, our recruiter will learn more about you and your story to check a potential fit for gravity9. This is also an opportunity to ask your questions about the role and company. This step might take around 60 mins.

2. Tech 1 Interview

In this meeting your potential future teammate will take a deeper dive into your experience and what you could bring to the team.
This step will take around 60 mins.

3. Tech 2 Interview

In this meeting your potential future teammate will take a deeper dive into your experience and what you could bring to the team.
This step will take around 60 mins.

4. Final Interview

You made it to the very last stage! Here we already strive to cooperate with you and give you an opportunity to meet our leadership team during this informal talk. This step will take around 30 mins.


Thank you for considering the opportunity to be a part of our growing journey. We look forward to the possibility of working together and achieving great things.

Role Description

We are looking for a smart, enthusiastic frontend software engineer with a keen interest in current technology and engineering. Using your experience of React.js and software engineering best practices, you will be involved in the design and implementation of modern frontend applications that are transforming industries. You will take an active part in team discussions and code reviews and you will work collaboratively with your colleagues to identify, prioritise and deliver features which bring value to our clients.

The role will involve developing new user-facing features using React.js, translating designs and wireframes into high quality code and optimizing components for maximum performance across a vast array of web-capable devices and browsers

We believe small, multi-disciplinary teams are most effective in delivering complex change. As such, we are looking for someone with a collaborative mindset who is happy to be flexible and take on different responsibilities over the lifetime of our projects.

Job requirements

Role requirements - technical skills and experience

This role will suit a highly capable developer with at least 5 years overall experience, including two years working with React.js. Skills and experience must include:

  • Strong proficiency in JavaScript (ES6+) and Typescript

  • Strong proficiency in CSS

  • Thorough understanding of React.js and its core principles including hooks

  • Experience with popular React.js workflows (i.e. Redux)

  • Experience with React Testing Library and Jest

  • Familiarity with RESTful APIs

  • Knowledge of modern authentication mechanisms, such as JWT, OAuth 2.0, OpenId Connect

  • Familiarity with modern front-end build pipelines and tools

  • Experience with common front-end development tools such as Babel, Webpack, NPM, etc.

  • Ability to understand business requirements and translate them into technical requirements

  • Experience working directly with UI/UX designers on creating UI

  • Excellent command / highly proficient in spoken and written English (working directly with UK/US based clients)

  • Development methodologies: Familiarity with agile working and test-driven development. Use of Git and JIRA

  • Education: An excellent result in computer science or another STEM subject is preferred, either at MSc or BSclevel, but alternative education paths will be considered

Nice to have:

  • Experience with microfrontends

Key attributes and behaviours to succeed in this role will be:

  • Delivery focus - strong analysis and problem-solving skills. Ability to evaluate, design and implement effective solutions. Flexibility to adapt skills to a spectrum of client engagements, use cases and modes of change delivery.

  • Exemplary standards of personal integrity and respect for others – professional approach to all aspects of client engagement and collaborative team working, able to quickly build relationships based on trust and transparency. Strong presentation and written and verbal communication are essential given the client facing nature of the role.

  • Value driven - Creative thinking, with aptitude for innovation and strong desire to exceed client expectations.

  • Energy – positive attitude and determination to learn and succeed.

🎯 Who is this job for?

gravity9, a fast-growing consultancy building modern digital products, is creating a talent pool for future Senior Frontend Developers (React) in Poland (Kraków, WrocΕ‚aw, GdaΕ„sk) or fully remote Europe-based; candidates should bring 5+ years’ experience (2+ with React.js), strong JavaScript/TypeScript, CSS, React hooks, Redux, Jest/RTL, REST APIs, authentication (JWT/OAuth/OpenID), and build tools (Webpack, Babel, NPM), with bonus points for microfrontends experience; responsibilities include building performant React apps, translating designs to code, optimizing across devices, collaborating in small agile teams, and engaging in code reviews and TDD; the company runs a multi-stage recruitment process now, securing candidates for upcoming projects, and offers the chance to work on impactful, client-facing solutions with a collaborative, international team culture.

πŸ’¬ Potential Interview Questions

  1. How many years of experience do you have with frontend development and React.js specifically?
    I have over 5 years of frontend development experience, with more than 2 years focused specifically on React.js, building scalable, performant, and user-friendly applications.

  2. What JavaScript and TypeScript experience do you bring to the role?
    I have strong proficiency in modern JavaScript (ES6+) and TypeScript, applying them to write clean, maintainable, and type-safe code in production applications.

  3. How do you approach state management in React applications?
    I have solid experience working with React hooks and popular state management libraries like Redux, ensuring predictable and efficient handling of application state.

  4. What tools and practices do you use to ensure code quality?
    I rely on React Testing Library and Jest for unit and integration testing, conduct regular code reviews, and follow test-driven development practices to maintain high-quality code.

  5. What is your experience with authentication and API integration?
    I have implemented authentication using JWT, OAuth 2.0, and OpenID Connect, and I am experienced in consuming RESTful APIs to build secure, interactive applications.

  6. Which frontend build tools and pipelines have you worked with?
    I am proficient with Babel, Webpack, and NPM, and have worked with modern build pipelines to optimize performance and streamline CI/CD workflows.

  7. How do you collaborate with designers and translate designs into code?
    I work closely with UI/UX designers, ensuring accurate translation of wireframes and mockups into responsive, pixel-perfect, and user-centric interfaces.

  8. What is your experience working in Agile environments?
    I have worked in Agile teams using Scrum and Kanban, collaborating with cross-functional teams, managing tasks in JIRA, and delivering iterative value through sprints.

  9. Do you have experience with microfrontends?
    Yes, I have exposure to microfrontend architectures, contributing to modular, scalable, and independently deployable frontend components in larger systems.

  10. Why do you want to join this opportunity at gravity9?
    I am excited about contributing to impactful projects that transform industries, and I value gravity9’s emphasis on collaboration, technical excellence, and delivering innovative solutions for clients.

πŸ“‹ Job Summary

This company is an expanding digital consultancy that partners with global clients to deliver transformative technology solutions, specializing in modern frontend development with React.js and agile practices. Operating through small, multi-disciplinary teams, they emphasize collaboration, flexibility, and innovation to create high-value, user-centric applications across industries. With a culture rooted in trust, transparency, and professional growth, they provide engineers with the opportunity to work directly with international clients, contribute to impactful projects, and grow within a supportive and dynamic environment.

Required Skills

React

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