Frontend Developer (f/m/d)

### About the Company

adjoe creates the technology that powers growth and monetization for mobile apps. Its flagship product, Playtime Arcade, has helped it become a worldwide leader in rewarded advertising, a format where users receive in-app rewards for trying new apps. This creates a strong exchange of value between advertisers, publishers, and more than 770 million users each year.

### Role Overview

The Catalog team owns the key moment when users discover and choose ads inside the rewarded experience. With more than 200 million monthly visits, the frontend must render quickly, personalize well, and never feel sluggish. The platform is designed for extremely fast interaction, with sub-second time to interactive as a core requirement.

The stack includes React, Vite, TypeScript, Redux, RTK Query, Lerna, Material UI, Vitest, Kubernetes, AWS Spot Instances, and a config-driven engine that supports real-time layout changes and A/B experiments across more than 2,000 games.

### What You Will Do

• Build frontend applications and shared packages in a Lerna monorepo for a product with over 200 million monthly visits.
• Develop with React hooks and TypeScript while keeping bundles efficient through Vite, code splitting, and tree shaking.
• Create flexible interfaces that can adapt to changing layouts, typography, and colors for a config-based experimentation system.
• Use Redux and RTK Query to manage state and asynchronous data loading while supporting very fast response times.
• Apply strong web fundamentals, including HTML, CSS, JavaScript, async programming, HTTP methods, and JSON.
• Write meaningful unit tests with Vitest and follow SOLID principles to keep the codebase maintainable.
• Debug issues directly in the browser, inspect network activity, and work safely with Git in a continuous deployment environment.
• Partner with backend, QA, design, and product teams to deliver improvements to the rewarded ad experience.

### Requirements

• At least 2 years of overall software development experience.
• At least 1 year of practical experience with React and TypeScript.
• Hands-on experience with React hooks.
• Good understanding of UX and UI behavior, with the ability to adapt interfaces for different display variations.
• Experience with Material UI is a plus.
• Solid knowledge of HTML, CSS, core JavaScript, asynchronous programming, HTTP methods, and JSON.
• Experience with Redux and RTK Query for state and data management.
• Ability to write effective unit tests using Vitest.
• Comfort debugging in the browser and analyzing network requests.
• Familiarity with Git and collaborative development workflows.
• Interest in learning a complex technical environment that includes Kubernetes and AWS Spot Instances.

### Additional Information

Applications are welcomed from candidates around the world. Relocation support to Hamburg, Germany is available for those who want to join the team onsite.

### Why Join adjoe

• Take ownership of impactful work reaching 770 million users and helping shape the adtech space.
• Work in a fast-moving environment with frequent releases and short feedback loops.
• Collaborate openly and solve problems directly across teams.
• Join a diverse global organization with people from more than 40 countries.
• Be part of a positive team culture that values progress, wins, and energy.

### Equal Opportunity

adjoe welcomes applicants who will strengthen the company's diversity.

### Responsibilities

• Develop frontend applications and shared packages within a Lerna monorepo.
• Build and optimize React and TypeScript interfaces for a high-traffic product.
• Implement dynamic UI customization for experimentation-driven ad experiences.
• Manage state and async data flows with Redux and RTK Query.
• Use browser debugging, network inspection, and Git to resolve issues and ship changes safely.
• Work closely with backend, QA, design, and product partners to improve the product.

### Requirements

• 2 years of overall software development experience.
• 1 year of practical React and TypeScript experience.
• Experience with React hooks.
• Strong understanding of HTML, CSS, JavaScript, async programming, HTTP methods, and JSON.
• Experience using Redux and RTK Query.
• Ability to write unit tests with Vitest.
• Comfort with browser-level debugging and network analysis.
• Working knowledge of Git.
• Good eye for UX/UI behavior and layout adaptability.
• Material UI experience is a bonus.

### Perks \& benefits

• Work on a product that reaches 770 million users annually.
• Make an impact in a fast-paced environment with multiple releases per day.
• Collaborate with a diverse team across more than 40 countries.
• Relocation support to Hamburg, Germany is available.
• Join a culture that values direct communication, teamwork, and enjoyment at work.