Senior Front End Developer (React.js)

About the Role

Are you a senior front-end pioneer who thrives on turning complex product visions into high-performance user experiences? We are looking for a Senior Front-End Engineer to own, architect, and elevate our client's front-end ecosystem using React and TypeScript. If you are a proactive problem-solver ready to drive development standards and lead high-impact features from concept to production, this is your next big career move.

About the Client

Our partner is a dynamic tech powerhouse building cutting-edge product engineering solutions across Fintech, iGaming, and Marketing. They turn innovative ideas into high-performing engines and launch them at scale. As their exclusive recruitment partner, Lionhires manages their full-cycle talent acquisition, ensuring a seamless and candidate-first hiring experience.

What You Will Do

• Architect and Build: Design and implement scalable, maintainable front-end architecture using JavaScript, TypeScript, and React.js.

• Drive Engineering Standards: Own and elevate front-end development processes, best practices, and code quality.

• Collaborate Cross-Functionally: Work closely with Product, Design, and Back-End teams to translate complex business requirements into elegant technical solutions.

• Lead Feature Delivery: Spearhead end-to-end feature development from initial concept through to deployment and production.

• Optimize Performance: Ensure the highest levels of application responsiveness, speed, and optimization.

• Influence Technical Roadmap: Participate actively in architectural decisions, technical planning, and future-proofing the codebase.

• Communicate Internationally: Maintain clear technical documentation and interface effectively with external stakeholders in English when required.

What You Bring

Minimum Qualifications

• 5+ years of experience in dedicated Front-End development.

• Deep technical expertise in JavaScript (ES6+), TypeScript, and React.js.

• Proven leadership: A track record of owning, scaling, and improving engineering processes.

• Startup agility: Experience working in fast-paced startup environments with a strong ability to work independently.

• Architectural mindset: Strong structural thinking coupled with an open-minded, proactive, and solution-oriented approach.

• Language proficiency: Fluent written and spoken English for seamless documentation and external communication.

Preferred (Nice to Have)

• Experience working on large-scale, enterprise-level projects.

• Hands-on experience designing complex CRM or SaaS systems.

• Deep knowledge of modern state management libraries (e.g., Redux, Zustand).

• Experience with advanced performance optimization and building scalable UI systems.

• A strong grasp of UX principles and a product-focused mindset.

What's in It for You

• Competitive Compensation: Top-tier salary with annual performance and remuneration reviews.

• Relocation Support: A smooth transition with a full relocation package (flight tickets + 2-week hotel stay).

• Compliance & Security: Official employment following Spain/EU laws, including registration support for family members.

• Growth & Learning: Abundant L&D opportunities, challenging tasks, language development support, and partial class compensation.

• Work-Life Balance: 23 working days of annual vacation to ensure you stay rested and refreshed.

• Vibrant Culture: Team building activities, birthday gifts, and a Social Club hosting over 50 events per year (coming soon).

Our Recruitment Process

We respect your time and aim for a transparent, efficient hiring journey:

1. Introductory Recruiter Call: A casual conversation to align expectations and discuss your background.

2. Technical Interview: A deep dive into your architectural approach, technical expertise, and real-world problem-solving skills.

3. Final Team Interview: A culture and collaboration alignment session with the hiring team and leadership.

4. The Offer: If it's a mutual match, we will extend a formal offer to welcome you aboard!