Senior QA Engineer - Windows Internals

Our client is looking for a highly technical QA Engineer with deep expertise in Windows internals, networking, and application compatibility testing. You will be responsible for validating low-level functionality such as drivers, hooks, and system APIs across our Windows Secure Enclave platform. This is not a checkbox QA role — you’ll be reverse-engineering app behaviors, designing compatibility matrices, and creating regression suites that validate complex interactions between Windows components, 3rd party software, and integrations into the Windows ecosystem.

This role sits within a deeply technical team building endpoint security and system-level compatibility software for unmanaged or BYOD endpoints. You’ll work side-by-side with developers who write kernel-mode and user-mode code.

About the role:

1. Design and execute test strategies for low-level Windows functionality: file system filters, network stack integrations, kernel/user hooks, etc.
2. Test application compatibility for hundreds of real-world desktop applications in containerized/sandboxed environments.
3. Build and maintain robust manual and automated regression test suites.
4. Investigate complex system interactions, using tools like Process Monitor, WinDbg, ETW, and Sysinternals.
5. File, isolate, and document hard-to-reproduce defects with deep system context.
6. Collaborate with developers and product managers to understand technical requirements and corner cases.
7. Develop automation tools and scripts (Python, PowerShell, C#) to streamline regression and compatibility testing.

1. 5+ years of Windows QA or SDET experience, with a focus on drivers, internals, or endpoint security products.
2. Deep understanding of Windows OS internals (e.g., kernel/user-mode transitions, ALPC, WFP, NDIS, minifilters, etc.).
3. Proven experience testing file systems, registry behavior, networking stacks, service lifecycles, and Group Policy interactions.
4. Comfort working with debuggers, profilers, and diagnostic tools.
5. Strong experience validating application behavior in controlled/sandboxed environments.
6. Familiarity with compatibility testing of major enterprise apps (MS Office, Zoom, Teams, Citrix, VPNs, etc.).
7. Scripting and automation experience in Python, PowerShell, or C#.
8. Strong communication skills and meticulous bug reporting practices.

Salary Range: $6500 USD /month + Holidays

Unlimited PTO