Principal Backend Engineer

Principal Backend Engineer

King

Barcelona or Stockholm

Your Role Within Our Kingdom

Monetization & Rewards, one of the core pillars of King’s player-centric LiveOps platform. As Principal Backend Engineer, you will take the technical lead on building backend systems that are:

• Modular and easy to integrate;
• Tuned for performance, scalability, and reliability;
• Flexible enough to support experimentation and machine learning personalization;
• Secure, maintainable, and future-proof for years to come.

You will collaborate closely with game teams, client-side and platform developers to deliver systems that let us iterate fast, operate smoothly, and offer delightful monetization experiences to hundreds of millions of players around the globe.

You Will, Among Other Things…

• Architect, implement, and evolve Java libraries for store, inventory, offers, rewards and item handling across King games;
• Enable real-time personalization by integrating with backend pricing, catalog, and ML services;
• Provide reusable interfaces and APIs that empower game teams to move fast and stay focused on what makes their games unique;
• Lead by example in coding standards, system design, and performance tuning;
• Troubleshoot complex, real-world problems in production, especially under peak traffic loads;
• Lead and coach fellow developers, share knowledge, and contribute to team culture and technical direction;
• Collaborate across functions (C++, Front-end, ML, Product Management) to ensure systems are robust, compliant, and player-first;
• Participate in the recruitment and onboarding of new talent as we grow our foundations team.

Skills to Create Thrills

• 8+ years of professional software development experience, with deep expertise in Java;
• Strong background in highly scalable systems;
• Experience with performance-critical services;
• Passion for code quality, testability, and long-lived, maintainable systems;
• A collaborative spirit and a love for knowledge sharing and peer mentorship;
• Comfort with CI/CD workflows and agile ways of working;
• Solid grasp of security, compliance (e.g. GDPR), and privacy-aware architecture is a plus;
• Bonus: experience integrating with ML-powered pricing, backend economy services, or working in cloud-based ecosystems.

A Bit About You

You’re a systems thinker who enjoys the challenge of building infrastructure that unlocks value across an entire game portfolio. You understand the craft of Java backend development and love shipping high-quality code that players never see, but always feel.

You bring not only technical depth, but curiosity and openness. You thrive in environments where experimentation is encouraged and where “just enough process” enables rapid iteration without sacrificing quality.

And if you’re excited by the idea of shaping the future of game monetization through clean architecture, real-time feedback loops, and close collaboration with world-class teams, then we’d love to hear your story.

Bonus Points If You Also...

• Have experience with mobile game LiveOps or operating at scale in a game-as-a-service environment;
• Have built tooling or backend libraries used by other developers;
• Have worked in the gaming industry (but we’re open to great people from other industries too!).