Senior Frontend Engineer - ReactJS (m/f/d)

Why this role matters

At JOIN, we believe hiring should be easy, fast, and fair - for companies and candidates alike. That’s why we’re building intuitive, powerful recruiting software that helps businesses of all sizes find the right people effortlessly.

As our Frontend Engineer in Spain, you’ll join an established and growing engineering hub that has already become a strong part of our organisation. Our office there is no longer new. It is a stable and integrated setup with close collaboration across teams and locations.

You’ll play a key role in shaping the future of our product and platform, working with a modern tech stack to build robust, scalable features that create real impact. This is not about starting from scratch. It is about strengthening and further evolving a mature engineering environment, contributing to technical standards, and helping us continue to raise the bar together.

Tasks

What you’ll be doing

Your work will directly shape how thousands of users experience JOIN. As a Senior Frontend Engineer, you’ll take strong ownership of delivering high-impact features end-to-end.

What that looks like:

• Own frontend feature delivery end-to-end – from technical discovery and solution design to implementation, testing, rollout, and monitoring in production.
• Translate product requirements into scalable technical solutions, proactively identifying edge cases, UX trade-offs, and performance implications before implementation begins.
• Build complex, maintainable React components and application flows using TypeScript and modern frontend architecture principles.
• Drive technical quality within your scope by writing robust unit, and end-to-end tests and ensuring high reliability of shipped features.
• Actively contribute to architectural discussions, proposing improvements to frontend structure, state management patterns, performance optimisation, and scalability.
• Collaborate closely with Product and Design during discovery, challenging assumptions and ensuring solutions balance user experience, feasibility, and speed.
• Monitor and optimise performance and user experience in production, using metrics, logs, and analytics to continuously improve feature impact.
• Support incremental improvements to the Design System and shared components when feature development requires enhancements.
• Mentor less experienced engineers through collaboration and knowledge sharing (without formal people management responsibilities).

Who you’ll work with

• Our mission as Frontend Guild is to provide JOIN’s customers and their candidates with a smooth UX experience, simplified and beautiful UI, and rich functionality to achieve their goals by using our data-rich capabilities.
• We strongly believe that Frontend engineering should be collaborative with product and design teams, that our UI is diverse and has accessibility and security in mind.
• We take care of our guild’s tools by building a robust and Figma-synced Design System, code generators and coding conventions to create consistency, avoid wasting time on scaffolding and clutter, and focus on the business logic and customer value.
• Stability is our utmost priority, hence we write E2E tests for all scenarios and optimize performance to make our product feel a bliss to use.

Requirements

What we’re looking for

We don’t believe in checklists – but if most of these apply to you, we’d love to chat:

✔ 4+ years of experience as a Frontend Engineer working with modern JavaScript frameworks (React preferred).
✔ Strong understanding of TypeScript, HTML5, and CSS3.
✔ Solid experience with state management libraries (Redux, Zustand, or similar).
✔ Knowledge of API integration patterns and data fetching (REST, GraphQL).
✔ Familiarity with testing frameworks such as Jest, React Testing Library, or Cypress.
✔ Understanding of CI/CD pipelines and version control using Git.
✔ Experience working collaboratively in cross-functional Agile teams.
✔ Strong focus on performance, accessibility, and usability.

Bonus points for:

• Experience contributing to or maintaining a Design System.
• Familiarity with Figma and UI collaboration workflows.
• Exposure to backend concepts or full-stack environments.
• Experience with analytics or experimentation tools (e.g. Statsig, A/B testing).

Benefits

Our Values

❤️ People First – We put humans at the heart of hiring.

🚀 Own It – We take initiative and solve problems independently.

🛠 Work Smarter – Efficiency beats effort.

💡 Be Bold – Challenge the status quo and push boundaries.

At JOIN, we thrive in a fast-moving, collaborative environment, and we are looking for colleagues who do too. That means:

• We love collaborating in the office sharing knowledge with all colleagues, and we do understand the flexibility of working from home when needed
• We adapt quickly and embrace change in a growth-oriented startup environment
• We continuously challenge ourselves and each other to improve

This role might not be ideal if:

• You prefer a highly structured environment.
• You want a fully remote position.
• You prefer minimal change and a slower pace.
• You’re not excited about ownership and growth.

What’s in it for you?

🖥 Apple hardware – The best tools for the job (MacBook).

🏆 Team events – Brunches, sports activities, and quarterly gatherings in Berlin.

🌍 Productivity from Everywhere – 104 days per year remote (post-probation), following our hybrid policy.

🏦 Competitive salary – Tailored to align with your experience level.

🏠 Relocation support – Assistance with paperwork, travel, and one month of furnished accommodation.

What to expect from the hiring process

We respect your time and keep things transparent:

1️⃣ Intro call (~30 min) – Let’s see if we’re a good match.

2️⃣ Hiring Manager Review – Your profile is assessed for technical and team fit.

3️⃣ Hiring Manager Interview (~60 min) – Dive into expectations and team dynamics.

4️⃣ Technical Interview (~60–120 min) – Demonstrate your skills.

5️⃣ Meet the Team (Optional) – Connect with your future colleagues.

You’ll always know where you stand - no black holes, no ghosting.

We welcome applications from individuals of all ages, abilities, genders, religions and diverse backgrounds. If you need assistance during the hiring process or in the workplace, let us know!

Don’t meet every requirement? No problem! We’re always open to exceptional candidates and value diversity in all forms.

📩 Apply now – We’d love to connect with you!