Role: Senior macOS Cyber Security Engineer, Endpoint Security (C++/Swift)
Location: Remote (PST working hours)
Client: Accenture/Amazon
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.
Job 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.
