Senior Go Backend Developer (Catalog) (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.

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

• Production Golang Systems Expertise: You bring 5+ years of backend development experience, including at least 3 years writing Go in production distributed environments. You will build and maintain our +99% Go microservice architecture—interfacing with our TypeScript/React frontend—to reliably handle 2+ million daily publisher interactions and scale beyond hundreds of millions of monthly active users.
• High-Throughput Event Streaming: You have hands-on experience designing asynchronous microservice communication using event buses like Kafka, SQS/SNS, and Kinesis. You will build pipelines to collect billions of daily API events and aggregate them into our data lake for sub-second querying.
• High-Scale Data & API Optimization: You understand database internals and low-level web standards (HTTP protocol, Encoding, Regular Expressions). You will optimize queries across hundreds of terabytes of data across DynamoDB, MySQL, Druid, and Athena to reduce API response times and expose transparent, well-documented open APIs to enterprise partners.
• Data Science & Algorithmic Integration: You quickly grasp complex technical topics and applied mathematics. You will partner directly with our Data Science team to translate and integrate machine learning algorithms into adjoe’s core application, optimizing real-time ad targeting.
• Collaborative Technical Communication: You communicate fluently and precisely in spoken and written English. You will actively participate in peer code reviews and technical knowledge sharing across an international backend engineering team.
• Plus: Infrastructure & Cloud Tooling: Hands-on experience with Terraform (Infrastructure as Code), Docker containerization, or serverless infrastructure.

🌎 We welcome applications from talent worldwide and provide relocation support to Hamburg, Germany for those ready to join our team.

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.