About Us

At UserWise Services, we build and scale mobile games played by millions worldwide. Our focus is simple: move fast, deliver impact, and use modern tools—including AI-assisted workflows—to accelerate development and iteration.
The Role

You'll work on a proven, high-performing mobile game built with Objective-C and Cocos, helping evolve it for the next stage of growth. This is not a "build from scratch" role—it's about:
Improving a live product with real users
Making smart, high-leverage technical decisions
Using AI tools to accelerate development, debugging, and refactoring
Why This Role Is Interesting

Work on a game that already has traction and players
See your impact immediately in a live environment
Use AI as a force multiplier, not just a buzzword
Solve real engineering problems—not just greenfield abstractions
Who This Is For

Engineers who enjoy fixing, improving, and evolving real products
People who like high ownership and fast execution
Builders who prefer impact over perfection
What You'll Do

Maintain and extend a legacy Objective-C + Cocos codebase




Optimize performance, memory usage, and runtime behavior for mobile
Refactor and modernize systems without breaking live operations
Ship features, events, and improvements in a live-service environment
Use AI-assisted workflows (code generation, debugging, refactoring, test creation) to move faster
Collaborate closely with product, design, and analytics to drive impact
Identify quick wins vs. deep tech improvements and prioritize accordingly
What We're Looking For

Strong experience with Objective-C and iOS development
Hands-on experience with Cocos (Cocos2d-x or similar)
Experience working on live mobile games or shipped apps
Ability to navigate and improve legacy codebases
Strong understanding of performance optimization (CPU, memory, rendering)
Pragmatic mindset: you know when to refactor vs. ship
Comfortable leveraging AI tools (e.g., Copilot, ChatGPT, etc.) as part of your workflow
Nice to Hav

📌 Senior Mobile Engineer (Madrid)
🏢 UserWise
📍 Madrid