Senior iOS Developer (f/m/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.

Creating solutions that run on 13% of the world’s smartphones

The Mobile Integrations team builds the core technology that turns advertising from an interruption into a rewarded experience for 770 million users. We own the robust, lightweight,integration layer between our ad engine and the global mobile ecosystem, ensuring our technology operates with minimal overhead while reaching a massive portion of the smartphone market.

On the client side,our technology performs smoothly across 20 million daily SDK initializations. We build native Swift and Kotlin SDKs optimized for ms initialization and minimal binary overhead, with Unity, Flutter, and React Native wrappers that provide a unified API across the entire mobile ecosystem. Behind the scenes, a high-throughput Go and DynamoDB architecture handles the real-time state synchronization of millions of concurrent sessions. When your code runs on nearly one out of every seven smartphones on Earth, every millisecond of execution and every byte of memory counts.

Your Mission & Who We Are Looking For:

• Swift expert with SDK experience. You have 5+ years as an iOS developer with a CS degree or equivalent, and have built and maintained production SDKs before. At adjoe, you'll be developing native iOS SDKs that run on millions of iPhones daily, owning feature development and iOS specification implementation end-to-end.
• Deep iOS platform knowledge. You have a thorough understanding of iOS; SwiftUI, modern concurrency, clean architecture principles, and service lifecycles, not just the happy path, but the edge cases that only surface at scale across hundreds of millions of monthly active users.
• Quality is part of your workflow. You work closely with QA to develop and maintain automated testing strategies through CI pipelines. You don't hand off to QA, you build testability from the start.
• Stays current with the iOS ecosystem. You follow iOS framework evolution closely and actively bring new capabilities into the SDK when they're relevant. You know what changed in the latest iOS release and have an opinion on whether it matters.
• Cross-platform exposure is a plus. Experience with Kotlin, React Native, Flutter, or Unity helps when working across a mobile team that spans the full ecosystem. AdTech industry background is a strong plus.

🌎 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.