Senior Full Stack Next.js Developer (f/m/d)

ZEAL Network SE is a dynamic, international group of companies that has been creating exciting and innovative lottery experiences for over 20 years. As Germany’s largest provider of online lotteries through our brands LOTTO24 and Tipp24, and a trusted partner of Spain’s ONCE, the second-largest national lottery, we’re shaping the future of the lottery industry. We are passionate about driving innovation, as demonstrated by our newest brands, Freiheit+ and Traumhausverlosung, which bring fresh and exciting dreams to life. Additionally, through ZEAL Ventures, we invest in inspiring e-commerce start-ups like Omaze and DAYMADE, fueling fresh ideas and opportunities.

We are looking for a Senior Full Stack Next.js Developer (f/m/d) to join our team working on a new, innovative charity lottery product. As part of a small and highly experienced development team, you will contribute to building and scaling customer-facing features while continuously improving key user journeys and conversion flows.

Your Tasks

• Develop, maintain and continuously improve our web application using Next.js
• Take ownership of frontend topics and drive technical decisions
• Work closely with product, design, marketing and backend teams in a lean, agile environment
• Integrate and evolve RESTful APIs in collaboration with backend engineers
• Ensure high-quality implementation of UI/UX designs with a strong focus on performance and scalability
• Write and maintain tests to ensure reliability, security and performance
• Contribute to deployment, monitoring and overall application stability together with DevOps
• Identify and drive improvements in performance, user experience and conversion
• Measure, analyze and iterate on product features based on data

What You Offer Us

• Strong experience as a Senior Full Stack or Frontend Engineer with a focus on modern web technologies
• Deep expertise in JavaScript, React and Next.js (App Router, Server Components, Server Functions)
• Proficiency in TypeScript, HTML5 and CSS3
• Hands-on experience with modern frontend tools such as Tailwind CSS, React Hook Form, TanStack Query, Zod or similar
• Experience building responsive, mobile-first applications
• A strong “you build it, you run it” mindset and experience working with production systems
• Ability to write clean, maintainable and performant code and design scalable architectures
• Solid experience integrating and working with REST APIs
• Strong understanding of web performance and optimization techniques
• Experience with modern development tools and a strong interest in leveraging AI to improve development workflows
• Ability to translate business requirements into technical solutions
• Proactive and outcome-driven: you take ownership, think in products, and drive topics forward
• Strong communication skills and the ability to work effectively in cross-functional teams

What We Offer

• State-of-the-art technologies and an agile environment (Check our Tech Radar: https://lotto24.github.io/tech-radar/)
• A modern, dynamic culture grounded in the success of a leading-edge e-commerce company.
• A talented team of ambitious, like-minded colleagues where your knowledge and ideas truly make an impact.
• Ongoing personal growth, supported by an annual development budget of €1,500 to invest in your professional development.
• Trust and autonomy, no micromanagement, just confidence in your ability to deliver and excel.
• Flexible work options with a hybrid setup focused on results.
• Unlimited vacation days in addition to your yearly 30-day vacation allowance.
• Opportunity for workations abroad using our WorkFlex tool.
• Monthly mobility allowance of €30 to use on the mobility option of your choice (e.g., the Deutschlandticket), plus access to a company bike leasing program.
• Company pension scheme, provided in partnership with Degura, to support your future financial security.
• Subsidized EGYM WELLPASS membership, with a contribution of only €25 per month, giving you access to a wide range of gyms and sports options across Germany.
• Monthly company events, team activities, and informal gatherings, including our popular company-wide lunches provided four days a week.

Not ticking every box or think you’ve got that unique set of skills we haven’t realized we need? Get in touch anyway, we’re always looking to add great people!