Software Engineer - Private Cloud Compute, On-Device Client Frameworks

Job Description:

The Private Cloud Compute (PCC) team builds Apple's privacy-preserving cloud inference platform - the system that lets generative-AI features on iPhone, iPad, Mac, and Vision Pro reach into the cloud without compromising user privacy. We are looking for a Software Engineer to join the team that builds the on-device client side of that pipeline: the system frameworks and sandboxed services that every Apple Intelligence and Foundation Models request flows through before it ever leaves the device. This is system-level Apple platform work. You will design and ship the Swift frameworks that turn high-level inference requests into a compact wire protocol, manage long-lived connections, stream multimodal output back to client apps - all under strict process isolation and privacy guarantees. Your code will run on every device that uses Apple Intelligence - and the bar for correctness, performance, and privacy is set accordingly.
You will be a key contributor to the Swift frameworks and XPC services that connect on-device apps and system daemons to PCC. Day-to-day responsibilities include: Designing and evolving the on-device client SDKs and the XPC services they sit behind, balancing API ergonomics for client teams with the strict process-isolation and attestation guarantees required by PCC. Implementing high-throughput, low-latency request paths: protobuf serialization of inference payloads, payload compression, multi-turn session state and lifecycle, retry/cancellation semantics, and streaming of incremental model output back to clients. Owning concurrency and resource management across async/await, AsyncStream, and GCD - including correct cancellation, back-pressure, and lifetime management of long-lived XPC connections. Building the telemetry, signposts, and privacy-audited logging that let on-call engineers diagnose request failures across device, cloud, and inference layers without exposing user data. Collaborating closely with the PCC server-side, Foundation Models, attestation, and platform-frameworks teams; writing design documents, leading reviews, and mentoring engineers on Apple platform fundamentals. Profiling on real hardware with Instruments and driving down memory, latency, and energy costs in the request path - these libraries run on every device, on every inference, so every microsecond matters.
Experience developing complex, system-level frameworks, daemons, or background services for iOS and macOS (beyond standard UI-focused app development). Strong programming proficiency in Swift, alongside experience with Objective-C or C/C++ for lower-level system integration. Deep understanding of concurrency (Swift Concurrency, GCD), memory management, and asynchronous network programming.
Experience designing or evolving wire protocols (e.g., Protocol Buffers), data-streaming pipelines, or connection management. Hands-on experience with Apple's Inter-Process Communication (XPC) to bridge sandboxed applications and system services. Familiarity with secure communication protocols, cryptography, or privacy-preserving architectures. Working knowledge of ML concepts and frameworks and proficiency in performance profiling with Instruments, and experience implementing robust client-side telemetry and logging using native Apple APIs. Familiarity with end-to-end systems that span device, network, and server tiers, and comfort reasoning about failure modes across that boundary