Machine Learning Engineer – LLMs, Agent Systems, and Simulation Tooling, Siri Core Modeling

Summary

Join the team redefining what a deeply personal and integrated assistant can be. As part of the Siri organization, you will help shape one of the world's most widely used AI assistants, powered by our next-generation of Apple Intelligence, with capabilities like personal context understanding and on-screen awareness, built with privacy from the ground up. Your work will have direct, meaningful impact for users across iOS, iPadOS, macOS, watchOS, and visionOS. This is a rare opportunity to build at the intersection of cutting-edge AI and human-centered design, shipping technology that is centered around users and their needs.

Description

Join a pioneering team shaping the future of voice-first, agentic platforms. As a Senior Machine Learning Engineer, you’ll help define how next-generation intelligent agents reason, plan, and interact with people through natural voice and multimodal experiences. You will develop the foundations of scalable LLM reasoning systems that will power the next wave of human–AI interaction. We’re seeking a senior ML engineer with strong expertise in large language models and agent-based systems to build the core reasoning and simulation capabilities behind a future platform for agentic voice experiences. You will work on advancing how LLMs plan, adapt, and evaluate actions in realistic environments, contributing to the development of reliable and trustworthy AI agents. Your work will focus on developing robust infrastructure and tooling for training, simulation, and evaluation of agentic LLMs. You’ll design and run experiments in simulated environments, build scalable evaluation pipelines, and help integrate agent behaviors across client and backend systems. This role is an opportunity to push the boundaries of reasoning, adaptive behavior, and platform architecture for agent-based intelligence. You will collaborate closely with ML scientists, applied researchers, and product engineers to transform early research into deployable systems. Together, we will shape a platform that empowers developers and end-users to build rich, voice-driven AI experiences.

Responsibilities

Design and implement scalable simulation and evaluation frameworks for LLM-based agents
Collaborate with ML researchers to translate novel reasoning approaches into production-grade systems
Develop infrastructure for training and experimentation with agentic behaviors
Integrate agent reasoning capabilities into client-side and backend environments
Drive iteration speed by creating reliable tooling for experimentation, prototyping, and deployment

Minimum Qualifications

Bachelor’s degree in Computer Science, Machine Learning, or related quantitative field, with 3+ years of relevant industry experience
Strong skills in Python (preferred) and at least one other programming language
Proven experience in ML engineering, including system design, training pipelines, and deployment workflows
Deep understanding of agent-based simulation, agentic RAG systems, and LLM evaluation methodologies
Ability to balance long-term platform vision with pragmatic short-term delivery in fast-paced environments

Preferred Qualifications

Experience deploying LLM models in research or production contexts
Knowledge of adaptive feedback loops, reinforcement learning, or interactive agent design
Familiarity with client-backend integration for AI-driven applications
MS or PhD in Computer Science, Machine Learning, or a related field

Pay & Benefits — Cupertino, California, United States

At Apple, base pay is one part of our total compensation package and is determined within a range. This provides the opportunity to progress as you grow and develop within a role. The base pay range for this role is between $150,400 and $277,600, and your base pay will depend on your skills, qualifications, experience, and location.

Apple employees also have the opportunity to become an Apple shareholder through participation in Apple’s discretionary employee stock programs. Apple employees are eligible for discretionary restricted stock unit awards, and can purchase Apple stock at a discount if voluntarily participating in Apple’s Employee Stock Purchase Plan. You’ll also receive benefits including: Comprehensive medical and dental coverage, retirement benefits, a range of discounted products and free services, and for formal education related to advancing your career at Apple, reimbursement for certain educational expenses — including tuition. Additionally, this role might be eligible for discretionary bonuses or commission payments as well as relocation. Learn more about Apple Benefits

Note: Apple benefit, compensation and employee stock programs are subject to eligibility requirements and other terms of the applicable plan or program.

Application Deadline

Apple accepts applications to this posting on an ongoing basis.