Why this role matters

JOIN helps thousands of businesses find the right people — faster, fairer, and with less friction. Our platform handles millions of candidate interactions, and our clients praise JOIN’s attention to detail and unmatched user experience.

We’re looking for a Senior Frontend Engineer to join our central office in Berlin. You’ll be stepping into a mature, integrated team and pushing it forward: improving our architecture, raising our quality bar, and shipping features that tens of thousands of users rely on every day.

Tasks

What you’ll be doing

You’ll own features end-to-end — from discovery through to production monitoring:

Ship high-impact features. You’ll take a product requirement, poke holes in it with Product and Design during discovery, architect the solution, build it in React + TypeScript, test it with Playwright and Cypress, and monitor it after launch. You’ll flag edge cases and UX trade-offs before they become problems.
Raise the technical bar. You’ll contribute to architectural decisions — state management patterns, performance optimization, scalability. You’ll write and advocate for TEPs (Technical Execution Plans) when changes need broader alignment. You’ll write robust unit and E2E tests because we take stability seriously — if it ships, it works.
Evolve the Design System. Our component library is Figma-synced and actively maintained. When your feature work surfaces gaps, you’ll improve shared components so the whole team benefits.
Make others better. You’ll contribute to our culture of knowledge sharing through pairing, code review, and knowledge sharing day-to-day collaboration — not through formal management, but through the work itself.

Our stack

React with TypeScript — everything is typed, no "any"s
Playwright for UI testing, Cypress for end-to-end testing
Figma-synced Design System with code generators and coding conventions
Zustand for state management
Modern.js and Turborepo to power out microfrontends monorepo architecture.
REST and GraphQL for data fetching
CI/CD pipelines, Git-based workflows, lots of automations
Analytics and experimentation tooling

How we work

Our Frontend Guild believes frontend engineering is a craft, not just implementation. A few things that shape our culture:

TEPs over gut feelings. We write Technical Execution Plans for significant changes — decisions are documented and thought through, not dictated.
Stability is a point of pride. We write E2E tests for all scenarios and optimize performance until the product feels effortless. Our users shouldn’t have to think about whether something works — it just does.
Design is a partnership. Engineers and designers sit together, sketch together, and challenge each other’s thinking — in person and in Figma, not just in handoff tickets.
Security is a default , not an afterthought.
We invest in tooling. Code generators, coding conventions, a living Design System, and AI-assisted workflows so engineers spend time on business logic, not scaffolding. Our product development lifecycle is future-proof.

Requirements

What we’re looking for

We don’t believe in checklists – but if most of these apply to you, we’d love to chat:

✔ 6+ years building production frontends with modern JavaScript frameworks (React strongly preferred)

✔ Deep comfort with TypeScript, HTML5, and CSS3

✔ Solid experience with state management (Zustand or equivalent)

✔ Hands-on with API integration — REST, GraphQL, or both

✔ Experience writing meaningful tests (unit and E2E)

✔ Familiarity with CI/CD and Git workflows

✔ Track record of working in cross-functional Agile teams — you collaborate with Product and Design, not just other engineers

✔ Strong opinions on performance and usability — backed by data when possible

Even better if you bring:

Experience building or maintaining a Design System
Comfort working in Figma alongside designers
Exposure to backend concepts or full-stack environments

Benefits

Our Values

JOIN Solutions AG