QA Automation Engineer (UI and API) (m/f/d)

adjoe builds the technologies behind mobile apps growth and monetization. With our core product Playtime Arcade , we've become the global leader in rewarded advertising, an ad unit built on a simple premise: users earn real in-app rewards for engaging with new apps. The result is one of the most effective value exchanges in adtech, connecting advertisers and publishers with over 770 million users annually.   Serving 2,000+ Distinct Ad Experiences With Sub-Second Time to Interactive The rewarded ad experience is where the value exchange becomes real, the second a user decides whether to engage or scroll past. The Catalog team owns that moment, designing how users discover and interact with the most relevant ads. With over 200 million monthly visits , there's no room for slow rendering or poor personalization. Performance and relevance have to be perfect on every request. The system runs on AWS Spot Instances spare compute capacity that can disappear at any moment, yet our system is built to stay online without any interruption for the user. Backed by Kubernetes with event-driven autoscaling, everything is tuned for millisecond-level data retrieval so the experience never feels slow, even at 200 million monthly visits . The frontend is built on React and Vite , leveraging Code Splitting and Tree Shaking to keep core bundles lean and Time to Interactive under a second. On top of that, a config-driven engine lets the team customize the entire ad experience or run A/B experiments per more than 2000 games on the fly, ensuring the right ad reaches the right user while continuously moving conversion rates in the right direction. Your Mission & Who We Are Looking For: Playwright and TypeScript are your primary tools. You have 3+ years in QA Automation with professional-grade proficiency in Playwright and TypeScript/JavaScript. At adjoe, you'll own end-to-end test suites covering complex UI interactions, API logic, and the communication between our offerwall/catalog and the SDK. You are comfortable testing the JS-to-Native bridge that connects offerwall interactions to SDK events like reward pings and user attribution. HTTP fluency is non-negotiable. You have extensive experience testing RESTful APIs — request/response payloads, status codes, contract testing across microservices — using Playwright, Postman, or Insomnia. You know how to mock and stub dependencies, and you don't stop at the happy path. You test all the way to the datastore. You verify that frontend actions correctly reflect in DynamoDB, Redis, and MySQL by querying databases directly within your test scripts. You also monitor network transfer rates, file size optimization, and database architecture efficiency beyond explicit test requirements. AI-assisted testing is already part of your workflow. You use AI coding assistants to write cleaner test code, generate synthetic test data, and implement self-healing UI tests. You stay current on AI-led QA trends and apply them in production. Quality gate owner, not just a tester. You own the CI/CD pipeline quality gate, coordinate with infrastructure, take an active role in sprint and release planning, and flag architectural risks early. You translate complex bugs into actionable feedback for both developers and stakeholders. Understands the business, not just the code. You have a solid understanding of the mobile adtech industry and adjoe's business model — enough to contribute meaningfully to product strategy and prioritize issues by real business impact. 🌎 We welcome applications from talent worldwide and provide relocation support to Hamburg, Germany for those ready to join our team. What’s in It for You? At adjoe, you’re not here to just close JIRA tickets, you’re helping build the infrastructure behind one of the most impactful platforms in adtech. The systems you work on will reach hundreds of millions of users and power billions of decisions every day. Go Big. Own projects with impact on 770M users and push adtech boundaries. Move Fast. Ship solutions multiple times a day, learn from results, and keep momentum. Be Direct. Solve problems openly and collaborate across teams. Thrive Together. Grow with a diverse, global team of people from over 40 different countries that learn from each other.   Have Fun. Celebrate wins, enjoy daily victories, and bring your energy. Skip writing cover letters. Tell us about your most passionate personal project, your desired salary and your earliest possible start date. We are looking forward to your application! We welcome applications from people who will contribute to the diversity of our company.