Senior Mobile Systems Engineer (iOS Focus)

What You'll Do

• Lead design and implementation of complex mobile platform integrations across the Graykey product.
• Debug hard problems that span multiple layers: Python, native C/C++, and mobile OS userspace and kernel behavior.
• Own root cause analysis on issues that require reading crash dumps, kernel panics, and disassembled binaries.
• Drive implementation from design through system integration, testing, and production.
• Mentor engineers on the team and help raise the technical bar through code review.
• Collaborate with firmware, product, and other engineering teams across the company.

What We're Looking For

iOS internals (!!!). This is the hard requirement. You need to have spent real time here, not just read about it:

• A-series/M-series SoC architecture: AP/SEP boundary, iBoot, DFU, restore mode.
• XNU kernel fundamentals: IOKit, kernel extensions, and how to actually debug at that layer.
• Memory protection: ASLR, PAC, and PPL.
• Code signing, entitlements, and the full trust chain.
• Sandboxing, container isolation, and platform-level IPC.
• Secure Enclave: its role in key management and where its boundaries are.
• Data protection classes, file system encryption, and key derivation.
• Keychain internals: what’s happening underneath the API.

iOS internals is a specialty in its own right. Android or other mobile platform experience is useful because the role also works on Android and on the Graykey product directly, but it does not substitute for iOS depth. Plan to bring iOS internals and pick up the rest on the job, not the other way around.

You DON’T need to be an Exploit Developer or Vulnerability Researcher. You DO need to read iOS internals fluently enough to integrate work into a product that runs across many device generations and iOS versions without breaking.

Python (!!!). Critical, not optional. We use Python extensively and at production scale. This isn’t scripting or tooling. You need to be strong here: type systems, packaging, performance, and writing code that doesn’t get rewritten by the next person to touch it. Python is load-bearing in this stack and weak Python in this role causes real problems.

Objective-C, C/C++, Systems programming, memory management, and low-level interface work. Meaningful time will be spent here.

General

• 8+ years of professional engineering experience, with at least 4 years working at the iOS platform layer.
• Experience with cross-compilation toolchains and embedded build systems targeting ARM64.
• Comfortable debugging remote devices and reading crash dumps and core files.
• Strong with git and senior-level code review workflows.

Nice To Have

• Reading-level reverse engineering skills with IDA Pro, Ghidra, or Binary Ninja, enough to make sense of stripped binaries you didn’t write.
• Objective-C runtime internals: method swizzling, dyld, class-dump.
• Android internals: SELinux, Binder IPC, TrustZone, dm-verity.
• Embedded systems background: real-time operating systems, kernel programming on resource-constrained hardware.
• Background in digital forensics, incident response, or law enforcement tooling.