About this role
Accepting applications until: 31 July 2026
Job Description Your Role: Junior Java Developer – DAX Exchange
Are you an early-career engineer who wants to build high-performance systems that power digital advertising at scale?
As a Junior Java Developer – DAX Exchange at Global, you’ll join a small, focused team building performance-critical services in modern Java. You’ll work on the matching engine that connects advertisers with outdoor screens and, over time, live radio and on-demand audio. You’ll contribute to production code from day one and learn how real-time systems are designed, built and run in the cloud.
Key Responsibilities
• Backend development (40%): Contribute to the DOOH Scheduler and DAX Exchange, delivering features, fixes and enhancements across the platform using modern Java.
• Quality and reliability (20%): Write clean, well-tested and maintainable code that meets the team’s standards for performance, resilience and observability.
• Operational support (20%): Help monitor, troubleshoot and maintain production services, gaining experience with supporting real-time, always-on systems.
• Learning and collaboration (20%): Pair with senior engineers, participate in code reviews and technical discussions, and support continuous improvement in how the team works.
What You’ll Love About This Role
Think Big: Help build the matching engine that powers programmatic advertising across outdoor screens in the UK, with growing opportunities across live radio and digital audio. Own It: Ship code that runs in production, take responsibility for your changes and see the direct impact of your work on a critical platform. Keep it Simple: Learn to design clear, focused services and straightforward solutions to complex performance and scalability challenges. Better Together: Work in a small, supportive team where you’ll receive mentoring, regular feedback and a clear path from junior to mid-level.
What Success Looks Like In your first few months, you’ll have:
• Contributed working, well-tested code to the matching engine and related services.
• Gained a solid understanding of the DAX platform, its data flows and performance requirements.
• Learned and applied the team’s development practices, tooling and deployment workflows.
• Helped support production systems, including monitoring, debugging and incident follow-up.
• Built strong working relationships with your teammates through pairing, reviews and regular collaboration.
What You’ll Need
• Technical foundations: Experience from a Computer Science (or similar) degree or equivalent practical background, with a strong understanding of core data structures and algorithms.
• Java and OOP fundamentals: Knowledge of Java and core object-oriented concepts such as inheritance, composition and common design patterns.
• Engineering practices: Familiarity with Git, basic Unix/Linux commands and working within an agile software development environment.
• Attention to detail: A careful, methodical approach to writing, reviewing and testing code.
• Growth mindset: Curiosity about how software interacts with hardware and networks, and an interest in learning more about cloud infrastructure, containerisation and real-time systems.
• Nice to have (not essential): Interest in low-level performance, networking or systems programming; exposure to AWS or other cloud platforms and/or containerised environments; curiosity about digital advertising, media or high-throughput real-time platforms.