Why Screen Share Safety Matters
Most technical interviews include a screen sharing component. Coding exercises, system design whiteboarding, portfolio reviews — at some point, you will be asked to share your screen. If your AI interview assistant is visible when you do, the consequences range from awkward to career-ending.
Understanding the technology behind screen share safety is not just academic — it is the difference between a tool you can trust and one that might betray you at the worst possible moment.
How Screen Sharing Actually Works
When you click “Share Screen” in Zoom, Meet, or Teams, the application calls your operating system’s screen capture API. On Windows, this is the Desktop Duplication API or Windows Graphics Capture API. On macOS, it is the CGWindowList API.
These APIs enumerate all visible windows and composit them into a single image that gets streamed to other participants. However — and this is the critical part — some windows can be flagged to be excluded from this capture.
The Two Types of Overlays
Browser-Based Overlays (NOT Safe)
Browser extensions add HTML elements to the browser window. These elements are part of the browser’s rendering tree — they are indistinguishable from the actual webpage content. When the screen capture API grabs the browser window, it captures everything including extension overlays.
Some browser extensions try to detect when screen sharing starts and hide themselves. This approach has several problems:
- Detection is not instant — there can be a visible flash before the overlay hides
- Not all platforms provide reliable screen-sharing detection events to extensions
- If the extension crashes or lags, it might not hide in time
Native Desktop Overlays (Safe)
Native desktop applications can create windows with special flags that tell the OS to exclude them from screen capture. On Windows, this is done by setting the window as a “layered window” with WS_EX_TOOLWINDOW and using SetWindowDisplayAffinity(WDA_EXCLUDEFROMCAPTURE). On macOS, setting the window’s sharing type to .none achieves the same result.
These are the same APIs that gaming overlays (Steam, Discord), streaming tools (OBS scene overlays), and accessibility tools use. They are well-tested, reliable, and supported by the operating system itself.
Craqly’s desktop application uses this approach. The overlay window is flagged at the OS level to be excluded from all screen capture APIs. It does not try to detect screen sharing and hide — it is simply invisible to capture at all times.
What About Screen Recording?
Some companies record interviews using screen recording software. The same principles apply — native overlays excluded from the screen capture API are also excluded from recordings. The overlay does not appear in any recording, whether it is Zoom’s built-in recording, OBS, or any other screen recording tool.
Can IT Departments Detect the Tool?
This depends on the setup:
Company-owned computers: If you are interviewing on a company-issued laptop with endpoint monitoring software, the IT department could potentially see which applications are running. However, they would only see the process name — they would not see the overlay content or know it is an interview assistant.
Personal computers: On your own computer, there is nothing to detect. The AI assistant is a normal desktop application. The overlay is invisible to screen capture. The audio processing happens locally.
Proctoring software: Some technical assessments use proctoring tools that monitor running processes. These might flag unknown applications. If you are taking a proctored exam (different from a video interview), be aware of this.
How to Verify Screen Share Safety Yourself
Do not take any tool’s word for it. Here is how to verify:
- Start the AI tool and make sure the overlay is visible on your screen
- Open Zoom/Meet/Teams and start a call (you can call yourself or a friend)
- Share your entire screen
- On another device (phone, tablet, second computer), join the same call
- Look at the shared screen view on the second device — the overlay should not be visible
- Also try sharing a specific window and a browser tab to verify all modes
This test takes 5 minutes and gives you complete confidence. Download Craqly and run this test before your first real interview.
The Bottom Line
Screen share safety is not a feature you can compromise on. If you are using an AI interview assistant during live interviews, it must be a native desktop application with OS-level overlay exclusion. Browser extensions, web apps, and tools that rely on “hiding when screen sharing starts” are not reliable enough to trust your career to.
Test it yourself. Verify it works on your specific computer, with your specific video platform. Then use it with confidence.