Senior Frontend Developer (React / TypeScript)

GemPool Recruitment; Ireland; On-site; EUR 90,000 - 130,000; Full time

Job summary

GemPool Recruitment is partnered with a global, data-driven B2B SaaS organization to hire a Senior Frontend Developer (React / TypeScript).

Joining a newly formed New Products team, you will build modern web applications and help modernize an existing, high-scale analytics platform. The engineering culture emphasizes rigorous automated testing and agentic AI-assisted development (Claude Code / Codex).

Qualifications

• 5+ years building production web applications in React, including 3+ years of TypeScript.
• Experience with Redux Toolkit, RTK Query, or similar client caching/data-fetching libraries.
• Experience upgrading large React codebases across major versions without halting feature delivery.

Responsibilities

• Architect and build modern web applications for a new product suite.
• Build data-heavy interfaces featuring configurable reports, drag-and-drop layouts, and virtualized tables.
• Work with real-time streaming data over WebSockets alongside REST APIs using Redux Toolkit and RTK Query.
• Maintain high quality standards targeting comprehensive test coverage using Jest, MSW, Storybook, and Playwright.
• Leverage agentic developer tools (Claude Code / Codex) to accelerate refactoring, framework upgrades, and test generation.

Skills

React

TypeScript

Redux Toolkit

RTK Query

WebSockets

Jest

Playwright

Storybook

Testing Library

Vite

Tools

Claude Code

Codex

Storybook

Vite

Job description

GemPool Recruitment is partnered with a global, data-driven B2B SaaS organization to hire a Senior Frontend Developer (React / TypeScript).

Joining a newly formed New Products team, you will build modern web applications and help modernize an existing, high-scale analytics platform. The engineering culture emphasizes rigorous automated testing and agentic AI-assisted development (Claude Code / Codex).

What You Will Do:

• Architect and build modern web applications for a new product suite.
• Build data-heavy interfaces featuring configurable reports, drag-and-drop layouts, and virtualized tables.
• Work with real-time streaming data over WebSockets alongside REST APIs using Redux Toolkit and RTK Query.
• Maintain high quality standards targeting comprehensive test coverage using Jest, MSW, Storybook, and Playwright.
• Leverage agentic developer tools (Claude Code / Codex) to accelerate refactoring, framework upgrades, and test generation.

What You Bring:

• 5+ yearsbuilding production web applications in React, including 3+ years of TypeScript.
• Strong experience with Redux Toolkit, RTK Query, or similar client caching/data-fetching libraries.
• Experience upgrading large React codebases across major versions without halting feature delivery.
• High testing discipline with TDD, Jest, React Testing Library, and Playwright.
• Experience designing performance-tuned, data-dense interfaces and dashboards.
• Hands-on familiarity using agentic coding tools (Claude Code or Codex) within day-to-day engineering workflows.

Nice to Have:

• Storybook and component design-system experience.
• Experience with real-time WebSocket UIs.
• Modern build tooling exposure (e.g., Vite).