We're seeking a Principal Software Engineer to join our Content Engineering team, focusing on architecting, building, and maintaining next-generation platforms for real-time data delivery that power Microsoft's multi-billion-dollar advertising business. Responsibilities: Define and drive the technical vision and architecture for large-scale, complex systems, ensuring scalability, reliability, security, and cost efficiency. Contribute hands-on to core code, complex implementations, and production issue resolution. Influence and align multiple teams and stakeholders across organisations through solid technical leadership. Partner with Product Management and leadership to translate business goals into robust technical solutions. Mentor engineers, raise the technical bar, and promote a culture of engineering excellence. Use AI tools and techniques to enhance engineering workflows, automate processes, and unlock new capabilities. Continuously refine data pipelines and system architecture to improve performance, reliability, and cost efficiency. Collaborate with Ads and Bing teams to enable new scenarios, integrate shared infrastructure, and deliver unified solutions. Provide production support by fixing bugs and resolving live-site issues to ensure system availability and reliability. Qualifications: Bachelor's Degree in Computer Science or related technical field AND 10+ years technical engineering experience with coding in languages including C, C++, C#, Java, JavaScript, or Python. Solid SQL expertise, Kafka, Hadoop, Hive and product development experience including memory management, multithreading, and performance optimisation, cloud expertise, AI. Proven experience designing and operating distributed, cloud-based systems at scale. Ability to influence without authority and drive alignment across multiple teams. Solid expertise in system architecture, data structures, algorithms, and software design patterns. Experience with microservices, data pipelines, or large data systems. Experience with CI/CD pipelines, version control systems (e.g., Git), and build tools. Preferred Qualifications: Experience with AdTech is a big plus. Experience building high-throughput, low-latency, or mission-critical services. Deep knowledge of Azure or other hyperscale cloud platforms. Experience with data-intensive systems, machine learning platforms, or large marketplaces. Track record of leading major architectural initiatives or platform transformations. Solid written and verbal communication skills, including technical design documentation. A collaborative team player with curiosity, a growth mindset, and a solid sense of responsibility. Exposure to AI/ML concepts and practical application of AI tools to solve modern engineering challenges.