Senior Software Engineer - LLMs, Agent Systems, and Simulation Tooling

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.

• Bachelor's degree in Computer Science or related quantitative field, with at least 4+ years of relevant industry experience with the following:
• Strong skills in Python (desired) and at least one other object-oriented programming language
• Proven experience in software engineering, including system design, development, testing, debugging, release and maintenance
• In-depth understanding of agent-based simulation frameworks, Agentic RAG systems, prompt engineering, and evaluation best practices for LLMs
• Ability to develop long-term strategic visions and implement scalable solutions in fast-paced, agile work environments

• 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 filed is preferred

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 $171,600 and $302,200, 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.

Apple is an equal opportunity employer that is committed to inclusion and diversity. We seek to promote equal opportunity for all applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, Veteran status, or other legally protected characteristics. Learn more about your EEO rights as an applicant

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