Senior Frontend Engineer (React + Next.js)

Quick Facts

• Role: Senior Frontend Engineer (React + Next.js)

• Focus: Agentic AI product user experiences and production-grade SSR frontends

Description

You will design and develop production web applications using Next.js with SSR, build AI/LLM-driven user interfaces, and evolve shared component libraries and a design system. The role emphasizes strong UI/UX, reusable and accessible frontend architecture, and maintaining production quality through testing and code reviews. You will also monitor and optimize performance (Core Web Vitals) and help ensure enterprise needs such as security, localization, and compliance.

Responsibilities

• Design and develop production Next.js SSR applications
• Build interfaces for AI and LLM features
• Develop reusable frontend component libraries and a design system
• Ensure reusability, accessibility, UX consistency, and solution quality
• Monitor and optimize frontend performance in production
• Maintain code quality: tests, code reviews, and frontend best practices

Requirements

• Minimum 5 years of frontend engineering experience
• Minimum 3 years of experience with React and modern TypeScript
• Strong Next.js knowledge with experience in SSR applications
• Familiarity with App Router and Server Components, including differences between SSR, SSG, and CSR
• Experience with complex state management (e.g., real-time collaboration, optimistic updates, multi-tenant isolation, large-scale data sync)
• Experience building AI/LLM UI (e.g., chat UI, streaming responses, semantic search)
• Experience optimizing performance and working with Core Web Vitals
• Experience with enterprise applications: accessibility, localization, security, and compliance
• Strong product sense and UI quality
• Experience working with AI tools and agents
• Strong communication and ability to justify technical decisions

Benefits

• Hybrid work model (3–4 days per week in the office) in Warsaw
• Senior-level role