Principal Mobile Engineer - Core Tech

About the role

Jagex is seeking a Principal Mobile Engineer to lead the technical direction of player‑facing mobile systems across the RuneScape franchise. You will shape architecture, drive large‑scale initiatives and ensure high‑quality, secure mobile experiences for a global audience.

Key responsibilities

• Own and drive mobile engineering initiatives across multiple projects, aligning with product goals and long‑term strategy.
• Define and evolve iOS and Android architecture for scalability, performance and maintainability.
• Lead delivery of complex technical solutions, coordinating dependencies across teams.
• Establish engineering standards, including code quality, testing and deployment practices.
• Identify and implement improvements to systems, services and processes.
• Collaborate with backend, product and platform teams to ensure seamless integration.
• Guide technical decision‑making, balancing short‑term delivery with long‑term system health.

Required profile

• Proven track record leading large‑scale mobile engineering initiatives in production.
• Deep expertise in native iOS (Swift/Objective‑C) and Android (Kotlin/Java) development.
• Strong experience defining mobile architecture integrated with backend micro‑services.
• Solid understanding of the software development lifecycle, CI/CD, testing and release practices.
• Experience working across teams to manage technical direction and delivery outcomes.
• Advanced debugging, performance optimisation and system‑level problem‑solving skills.
• Experience with C++ is a plus.

Required skills

• Swift
• Objective‑C
• Kotlin
• Java
• C++ (advantageous)
• Mobile architecture design
• CI/CD pipelines
• Automated testing
• Release management
• Debugging and performance optimisation

What we offer

• Private healthcare including dental plan.
• Discretionary annual performance bonus.
• Minimum 6% pension contributions.
• Life insurance and enhanced family‑leave policies from day 1.
• Flexible working hours and hybrid remote/on‑site model.
• 25 days annual leave plus bank holidays, with the option to buy/sell holidays.