Senior iOS Engineer - AI Platform

About the Role

Yo is building an AI inference platform that runs directly on smartphones - turning the phone in your pocket into part of a global AI network. You will own the iOS side: building the runtime that uses Apple Neural Engine to run real AI models on real devices while the phone sits on the charger.

This is a foundational hire. You set the iOS technical direction from day one and ship code that runs on millions of devices.

## Key Responsibilities

- Own the iOS SDK end-to-end - architecture, public API, distribution, versioning
- Build and maintain the iOS runtime that runs AI inference on Apple Neural Engine
- Make it fast, battery-friendly, and thermally well-behaved at sustained load
- Manage the iOS lifecycle correctly within Apple's background-execution rules
- Work with the Android engineer to keep the two platforms feature-aligned
- Ship to production and iterate against real-world telemetry

## Required Qualifications

- 6+ years iOS engineering experience
- Strong Swift; comfortable with C++ and Objective-C interop
- Deep understanding of iOS lifecycle, background execution, and App Store review
- Experience with system-level constraints: battery, thermal, memory pressure
- Has shipped production code that runs across a wide hardware range

## Nice to Have

- On-device ML experience (CoreML, MLX, ExecuTorch, llama.cpp on iOS)
- Apple Neural Engine optimisation; quantised model formats (INT4 / INT8, GGUF)
- Has shipped a public SDK or library used by other developers
- Cryptography fundamentals - end-to-end encryption, attestation, secure enclave
- Open-source contributions to ML inference projects

## What Success Looks Like (First 6 Months)

- Working iOS SDK shipped to a pilot user base
- Production telemetry showing measured battery and thermal impact
- Stable runtime across the range of supported devices
- Clean foundation for the team to build on

## Location & Logistics

- Remote / flexible (team in EU and US time zones)
- Competitive senior compensation, equity participation
- Reports to the CTO