Location
London

Hours
Full Time

Salary
Negotiable

About the Role
The Private Cloud Compute (PCC) team builds Apple’s privacy-preserving cloud inference platform — enabling generative-AI features on iPhone, iPad, Mac, and Vision Pro to access the cloud without compromising user privacy. We are seeking a Software Engineer to join the team responsible for the on-device client side of this pipeline: the system frameworks and sandboxed services that every Apple Intelligence and Foundation Models request passes through before leaving the device.

This role involves system-level Apple platform work where you will design and ship Swift frameworks that transform high-level inference requests into a compact wire protocol, manage long-lived connections, and stream multimodal output back to client apps — all under strict process isolation and privacy guarantees. Your code will run on every device using Apple Intelligence, with high standards for correctness, performance, and privacy.

You will be a key contributor to the Swift frameworks and XPC services connecting on-device apps and system daemons to PCC. Day-to-day responsibilities include designing and evolving on-device client SDKs and their underlying XPC services, implementing high-throughput, low-latency request paths including protobuf serialization, payload compression, session state management, retry/cancellation semantics, and streaming incremental model output.

You will own concurrency and resource management across async/await, AsyncStream, and GCD — ensuring correct cancellation, back-pressure, and lifetime management of long-lived XPC connections. Additionally, you will build telemetry, signposts, and privacy-audited logging to enable on-call engineers to diagnose request failures across device, cloud, and inference layers without exposing user data.

Collaboration is key, working closely with PCC server-side, Foundation Models, attestation, and platform-frameworks teams. You will write design documents, lead reviews, and mentor engineers on Apple platform fundamentals. Profiling on real hardware with Instruments and optimizing memory, latency, and energy costs in the request path are critical, as these libraries run on every device and inference.

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, with experience in 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
- Proficiency in performance profiling with Instruments and implementing robust client-side telemetry and logging using native Apple APIs
- Familiarity with end-to-end systems spanning device, network, and server tiers, and ability to reason about failure modes across these boundaries

About you
You are a detail-oriented engineer passionate about building high-performance, privacy-focused system software. You thrive in collaborative environments, enjoy mentoring peers, and take ownership of complex technical challenges. You have a strong commitment to quality, security, and user privacy, and you are motivated by the impact your work has on millions of Apple devices worldwide.

Qualifications
Relevant degree or equivalent experience in computer science or related fields is preferred but not mandatory. Demonstrated expertise in system-level programming and Apple platform development is essential.