Senior Frontend Engineer, AI Chat UI Platform

Relativity; Kraków; Hybrid; PLN 208,000 - 312,000; Full time

Benefits offered by this job

DTO

Parental leave

Equity program

Job summary

Relativity is hiring a Senior Frontend Engineer for the aiR Assist team in Kraków. You will own frontend delivery for AI chat and agent experiences, building scalable, accessible UI on a modular platform of micro-frontends and shared AI context services.

You will mentor peers, define frontend standards, and drive quality, performance, and maintainability across the cloud platform, collaborating with UX, Product, and Backend teams to quickly ship improvements.

Qualifications

• 4–6+ years of professional frontend development experience building large-scale web applications or enterprise platforms.
• Advanced proficiency with JavaScript (ES6+), TypeScript, and the modern React ecosystem, including hooks and concurrent rendering patterns.
• Experience designing reusable UI infrastructure, shared libraries, and scalable frontend abstractions.
• Strong experience with modular architecture, code splitting, lazy loading, and micro-frontend concepts.
• Experience with component libraries such as PrimeReact, Material UI, or similar frameworks.
• Strong responsive web design skills, including semantic HTML, modern CSS methodologies, and cross-device user experiences.
• Experience integrating with RESTful APIs and GraphQL services, and modern data-fetching solutions like React Query and Zustand.
• Familiarity with bundlers and monorepo tooling (Vite, Webpack, Nx, Turborepo).
• Hands-on testing with Vitest, Jest, Playwright, or Cypress.

Responsibilities

• Design and implement scalable, performant chat and agent UI using React, TS, and PrimeReact.
• Build AI-powered chat experiences with streaming responses and state management.
• Contribute to and consume from Relativity's micro-frontend platform and shared AI context services.
• Apply modularization, code splitting, and Nx monorepo practices.
• Ensure accessible, responsive UI across devices and WCAG standards.
• Collaborate with UX, Product, and Backend teams to ship continuous improvements.
• Define frontend standards for testing, performance, and maintainability.
• Own frontend test coverage with Vitest, Playwright, visual regression, and Storybook-driven development.
• Contribute to frontend CI/CD pipelines and component lifecycles.
• Mentor engineers and provide technical leadership across frontend initiatives.
• Explore AI-driven UI enhancements for customer-facing and internal experiences.

Skills

JavaScript (ES6+)

TypeScript

React

Reusable UI infrastructure

Modular architecture

Web accessibility (WCAG)

REST/GraphQL

Testing (Vitest, Playwright)

Tools

PrimeReact

Material UI

Vite

Webpack

Nx

Turborepo

Web Components

Module Federation

Jest

Playwright

Job description

Relativity is hiring a Senior Frontend Engineer for the aiR Assist team in Kraków. You will own frontend delivery for AI chat and agent experiences, building scalable, accessible UI on a modular platform of micro-frontends and shared AI context services.

You will mentor peers, define frontend standards, and drive quality, performance, and maintainability across the cloud platform, collaborating with UX, Product, and Backend teams to quickly ship improvements.