macOS Endpoint Security Engineer

Role: Senior macOS Cyber Security Engineer, Endpoint Security (C++/Swift) Location: Remote (PST working hours) Client : Accenture/Amazon Work Authorization: U.S. Citizen (USC) or Green Card (GC) holders only Requirement Type : Contractual Experience : 6-10 years, we can evaluate more senior as well but need to build a pyramid. W-2 Rate: $65 - $70/hr. J ob Description: About the work You'll work on the macOS sensor for CrowdStrike Falcon, an on-device security agent. It monitors file, process, network and identity activity, blocks malicious behavior, and streams telemetry to the cloud. The sensor runs entirely in user space as a System Extension. Much of the code is shared with Windows and Linux. The work requires high concurrency, high reliability, careful attention to memory & CPU usage and performance. Required

• Languages: modern C++ (C++17/20) and Swift 6 (async/await, actors, strict concurrency checking). Also Objective-C++ to bridge Swift, C++ and C APIs.
• macOS systems programming: Foundation and CoreFoundation, GCD and pthreads, POSIX/BSD APIs, Mach IPC, launchd daemons and agents, and XPC (C API and NSXPCConnection).
• Performance, debugging and test: o Profiling CPU and memory with Instruments and os_signpost. o Debugging with LLDB, crash logs and os_log. o XCTest, sanitizers, fuzzing, and xcodebuild-based CI. o Apple Silicon and Intel.
• Experience with codebases shared across Mac, Windows and Linux. Core skills (one or more of the areas listed below)
• Process model and IPC: launchd daemons and agents, and XPC (C API and NSXPCConnection).
• Endpoint Security and System Extensions: Endpoint Security clients handling both blocking (AUTH) events and notification events, user/MDM approval, upgrades.
• Network Extension: content filters, both flow-level (NEFilterDataProvider) and packet-level (NEFilterPacketProvider), and Network.framework.
• Security and crypto: Verifying code signatures (SecCode / SecStaticCode) and validating certificates (SecTrust), Keychain, Entitlements, hardened runtime, and macOS privacy permissions.
• Devices and storage: IOKit (hardware and device enumeration) and DiskArbitration (disk and volume events).
• Packaging and deployment: installers, notarization, and MDM configuration profiles deployed through Jamf, Intune or similar tools.
• Performance, debugging and test: Profiling CPU and memory with Instruments and os_signpost, Debugging with LLDB, crash logs and os_log, XCTest, sanitizers, fuzzing, and xcodebuild-based CI. Nice to have
• UI: SwiftUI and AppKit apps and app extensions.
• Testing against macOS and Xcode betas before public release.
• Experience shipping EDR/AV, network security or device-management products.