Principal Machine Learning Engineer, AI & Data Platforms (AiDP)

Our Principal Machine Learning Engineers are technical leaders who shape the direction of intelligent systems across Apple. In this role, you will own the end-to-end lifecycle of an internal generative AI System at global scale - from pre-training LLM strategies and reinforcement learning from human feedback (RLHF) through fine-tuning, alignment, evaluation, and production deployment. You will architect and deliver standalone AI-powered products and platform capabilities that operate reliably at global scale.

You will establish rigorous benchmarking and evaluation frameworks to measure LLM performance across accuracy, latency, safety, and fairness dimensions. You will drive model customisation strategies, including prompt engineering, parameter-efficient fine-tuning (LoRA, QLoRA), and full fine-tuning, tailored to diverse product requirements. You will design and build production-grade inference systems, working across Swift, Java, and Python to integrate ML capabilities seamlessly into Apple's ecosystem. As a senior technical contributor, you will set engineering standards, mentor engineers, and influence the technical roadmap for generative AI adoption across the organisation.