ZEXTER is a technology company developing its own full-stack platform for the digital entertainment and iGaming ecosystem. We build scalable technology solutions for operators, creators, and digital businesses, helping them launch, manage, scale and monetize their products more efficiently.
We are now looking for a Senior Frontend Developer to help us build and scale our in-house platform. This is a hands-on, product-focused role for someone with strong React and TypeScript expertise, solid experience building production-grade applications, and the ability to take ownership of frontend development in a growing product.
Responsibilities:
- Develop and maintain scalable, high-performance frontend applications using React, Next.js and TypeScript.
- Design and implement robust frontend solutions, contributing to architecture decisions and improving existing systems.
- Build and deliver end-to-end product features, collaborating closely with backend developers, QA, design and product.
- Ensure code quality, performance and reliability through testing, code reviews,



monitoring and continuous optimization.
- Contribute to development processes and frontend best practices, improving tooling, CI/CD, observability and overall engineering quality.

Requirements:
- 5+ years of commercial frontend development , including 3+ years with React , with experience owning and supporting production applications under real user load.
- Strong TypeScript skills: strict mode, generics, utility types, discriminated unions, and fully typed API contracts without any.
- Advanced React 18/19 & Next.js knowledge: hooks, render cycle, Suspense, Server/Client Components, App Router, SSR/SSG/ISR, middleware, caching and routing.
- Experience with TanStack Query , including query management, invalidation, SSR prefetching/hydration, persistent cache and optimistic updates.
- Ability to design and evolve large-scale frontend architecture : clear module boundaries, layered structure, public APIs, and g

📌 Senior Frontend Developer (España)
🏢 Zexter
📍 España