This role is for a systems engineer within the Siri organization, focusing on the development of an integrated AI assistant. The engineer will work on the harness that enables large language models to act effectively, ensuring responsiveness under tight constraints. Collaboration with senior engineers, researchers, and various teams across Apple is essential. The position emphasizes real-time performance and the ability to diagnose and improve system behavior.

• Bachelor's degree in Computer Science or a related field, with 2+ years of industry experience
• Strong programming skills in a systems language such as Swift, C++, Rust, Objective-C, or Go
• Solid foundation in concurrency, inter-process communication, and performance optimization
• Hands-on experience building LLM-powered systems such as agents, tool calling, or prompt and context design
• Daily use of agentic coding tools such as Claude Code, Codex, or Pi
• Ability to communicate clearly and make progress on ambiguous problems
• Experience with Swift and Apple platform development
• Experience building agent harnesses, orchestration frameworks, or multi-step tool-use systems
• Experience with model inference integration, streaming protocols, or latency-sensitive client-server systems
• Experience using evals to diagnose and improve LLM behavior
• Experience designing APIs or platforms adopted by other engineering teams
• Familiarity with privacy and security engineering in production systems
• Active engagement with current research and practice in agent harness design

• Develop and maintain the harness that enables large language models to act effectively
• Collaborate with senior engineers and researchers to enhance system performance
• Diagnose and resolve issues related to streamed responses and tool calls
• Measure and evaluate changes to the harness to understand their impact on model behavior
• Take features from design through production while growing ownership of the system
• Work closely with modeling, tools, and context teams as well as app and framework teams across Apple

• Employees at Apple are often offered comprehensive benefits that support physical and mental well-being—flexible medical plans, confidential counseling, onsite wellness centers at major campuses, and resources for fitness and daily life. Families typically receive fertility support, paid parental leave with gradual return, caregiving leave, and dependent-care guidance, while financial perks commonly include stock grants (with purchase discounts), 401(k) matching, and income-protection coverage. Employees also see robust time off, Apple University learning and tuition reimbursement, donation matching and paid volunteer hours, and deep product and partner discounts.