Working Student - Product & QA (f/m/d)

adjoe builds the technologies behind mobile apps growth and monetization. adjoe Ads is our programmatic in-app advertising platform that seamlessly connects advertisers and publishers through direct integration of our Android and iOS SDKs. Every ad decision happens in under 200ms across 10 million daily users, powered by real-time bidding algorithms and user quality prediction models that match the right ad to the right user at the right moment.

Where 50 Billion Daily Predictions Begin

The User Experience team is the origin point of adjoe Ads. Everything the system knows about a user, every prediction the ML models make, every bid placed in an auction. It all starts with code this team ships.

The team owns two responsibilities. On the SDK side, a native Kotlin and Swift code runs inside hundreds of publisher apps. It participates in 120 million daily auctions , renders ad creatives across multiple formats, and captures the behavioral signals that power 50 billion predictions per day . The constraint that defines this work: you're executing inside someone else's app, on someone else's device, with zero tolerance for instability. Every ad impression has to feel native and fast to the user.

On the analytics side, the dashboards, investigation tools, and data frameworks that turn raw data into decisions: real-time revenue performance across active campaigns, infrastructure cost visibility, and data quality assessments. If a number matters to the business or to engineering, this team makes it accessible.

Your Mission & Who We Are Looking For:

SDK & Mobile Game Testing: Playtest mobile games and manually test our SDK integrations to verify that ads load, display, and track correctly across target environments. You thrive in this role if you bring a technical mindset, natural curiosity about how apps work, and the ability to comfortably navigate digital tools.

Methodical Bug Reproduction: Execute step-by-step manual testing procedures and reliably reproduce bugs to maintain core product stability. This requires high attention to detail, patience, and the focus needed to run structured, repetitive QA tasks with consistent accuracy.

Actionable Technical Documentation: Document test findings and maintain internal testing guidelines so engineering teams can immediately act on issues. You need precise written and verbal communication skills to translate edge-case behaviors into clear, reproducible technical steps.

Product & Market Research: Conduct directed market and product research to supply actionable data directly to product managers for decision-making. You will succeed here by following clear processes, sticking to project guidelines, and adapting as research priorities shift.

Cross-Functional Task Rotation: Adapt to rotating projects across developers, product managers, and other stakeholders as testing needs evolve. We are looking for an enrolled university student in Germany who follows structured workflows dependable execution on cross-functional tasks.

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.

We welcome applications from people who will contribute to the diversity of our company.