Frontend Engineer React / UX (m/f/d)

HalloCharly / Zaitgeist; Berlin; On-site; EUR 85,000 - 110,000; Full time

Benefits offered by this job

Central office in Berlin

28 days vacation

Job summary

HalloCharly / Zaitgeist is seeking a frontend engineer to build features end to end with React and TypeScript, shaping UI across apps and ensuring accessibility by design. You’ll make AI actions transparent for staff and contribute to a unified design system with strong UX patterns.

You will design responsive, data-heavy interfaces, collaborate with founders, and write tests to keep performance high. This role requires hands-on UI work and close user interaction.

Qualifications

• Several years of experience with React and TypeScript in production.
• Strong UX sense: designed flows yourself — in Figma or directly in code — and talked to real users.
• Experience with accessibility and responsive design.
• Comfortable with data-heavy interfaces: tables, filters, charts.
• Backend awareness: REST, authentication and the basics of row-level security in Postgres.
• You use AI coding assistants every day: build fast first, then harden properly.
• Nice-to-have: German language skills, experience with public-sector software.

Responsibilities

• Build features end to end with React and TypeScript — from sketch to production in days.
• Design for people who aren't techies; accessibility (BITV/WCAG) is required.
• Make AI understandable: show what Charly did and why staff can correct it.
• Build a shared design system and consistent UX patterns across all apps.
• Write tests (Vitest, Playwright) and keep an eye on performance.

Skills

UX design

Accessibility

Data-heavy interfaces

Education

Bachelor-like degree or equivalent

Tools

React

TypeScript

Tailwind

Supabase

Vitest

Playwright

Next.js

PostgreSQL

REST API

Job description

Charly answers the phone for more than 100 German municipalities — around the clock, in over 30 languages, hosted in the EU. Town hall staff see Charly through our interfaces: they review conversations, maintain knowledge, read analytics and work with Schreibtisch, our AI workspace for public administration. Citizens also reach Charly in the chat on their town's website. Our team is small and ships fast: around 150 pull requests land in our repositories every month. What starts as a sketch today is often live within days.

Your Role

Build features end to end with React, TypeScript, Tailwind and Supabase — from sketch to production in days, not quarters

Design for people who aren't techies; accessibility (BITV/WCAG) is a requirement, not an afterthought

Make AI understandable: show what Charly did and why, and how staff can correct it

Build a shared design system and consistent UX patterns across all apps

Write tests (Vitest, Playwright) and keep an eye on performance

Your Profile

Several years of experience with React and TypeScript in production

A strong UX sense: you have designed flows yourself — in Figma or directly in code — and talked to real users

Experience with accessibility and responsive design

Comfortable with data-heavy interfaces: tables, filters, charts

Backend awareness: REST, authentication and the basics of row-level security in Postgres

You use AI coding assistants every day: build fast first, then harden properly

Nice-to-have: Next.js, German language skills, experience with public-sector software

What We Offer

Real ownership of the UX of all products, working directly with the founders

Close to users: you talk directly to staff in the municipalities

A beautiful and central office right at Rosenthaler Platz

28 days of vacation per year