Staff Machine Learning Engineer - Ads Signals Intelligence & Information Retrieval

Apple's Ads Signals Intelligence team is seeking a Staff Machine Learning Engineer to develop ML-driven signal platforms for ad retrieval and relevance. The role focuses on building content understanding systems using LLMs, knowledge graphs, and multimodal learning. You will work on semantic search, query understanding, and large-scale signal extraction to power Apple's advertising ecosystem.

• Design, implement, and scale ML systems that extract high-value semantic signals from structured and unstructured content.
• Contribute to retrieval and ranking pipelines using techniques in query understanding, semantic embedding, and dense/sparse indexing.
• Fine-tune and apply Large Language Models (LLMs) for NLP tasks like content labeling, rewriting, and semantic similarity.
• Construct and utilize knowledge graphs and entity linking systems for enriching creative and query signals.
• Work with multimodal data (e.g., combining text, image, and metadata signals) to build robust, cross-domain signal representations.
• Build core components for a content understanding platform, such as entity extraction, topic modeling, creative summarization, and taxonomy generation.
• Own experimentation, offline evaluation, and online validation of signal pipelines at massive scale.
• Collaborate across engineering, infra, and product teams to productionize systems while meeting Apple’s high standards for reliability and privacy.