Senior Machine Learning Engineer - LLMs, Agent Systems, and Simulation Tooling

Apple • Seattle, WA

74d

About The Position

Join the Siri Planner team as a senior experienced Software Engineer and play a pivotal role in crafting the future of virtual assistants. You'll contribute to revolutionizing how millions of Siri users worldwide interact with their Apple devices by working on groundbreaking technologies for LLM model reasoning. We're looking for a senior software engineer with a strong proficiency in ML systems and large language models to help build advanced reasoning capabilities for the Siri virtual assistant. We are a collaborative team of ML engineers, scientists, and software developers passionate about LLM planner modeling to build the next generation of the Siri virtual assistant. Your work will center on developing reliable, scalable tooling for training, simulation, and evaluation of LLMs and agentic systems. You'll also play a hands-on role in designing and running experiments in simulation, and integrating client-side components with backend systems into a production-ready testable environment. This is an opportunity to work with pioneering technologies that push the boundaries of LLM agent reasoning, system architecture, and rapid iteration. You'll collaborate closely with ML developers, client-side engineers, and deep learning leaders to bring enhanced LLM reasoning capabilities into production.

Requirements

• Strong proficiency in ML systems and large language models.
• Experience supporting ML teams or deploying LLM models in production or research.
• Knowledge of feedback mechanisms and adaptive agent behaviors.
• Experience integrating client-side applications or code with backend systems (APIs or custom protocols).
• MS or advanced degree in Computer Science, Machine Learning or related quantitative field is preferred.

Responsibilities

• Develop reliable, scalable tooling for training, simulation, and evaluation of LLMs and agentic systems.
• Design and run experiments in simulation.
• Integrate client-side components with backend systems into a production-ready testable environment.
• Collaborate with ML developers, client-side engineers, and deep learning leaders.

What This Job Offers

• Career Level: Senior
• Industry: Computer and Electronic Product Manufacturing
• Education Level: Master's degree
• Number of Employees: 5,001-10,000 employees