Using FaangCoder on HackerRank.
HackerRank is the most-used coding-interview platform — full-screen mode, tab-switch tracking, plagiarism similarity.
HackerRank's proctor stack is a tab-switch poller, a full-screen-mode flag, and MOSS-style plagiarism similarity on submitted code. None of those vectors target a kernel-mode overlay. FaangCoder runs alongside HackerRank in the browser, reads the problem text out of the V8 heap, and stays hidden from any Zoom/Meet/Teams screen-share the recruiter pairs with the round.
Will it run on HackerRank?
Operating system
Windows 10 / 11 (x64)
Browser
Chrome / Edge / Firefox 110+ — HackerRank runs in any modern Chromium or Gecko build
Overlay model
Native Win32, no browser extension, no DOM injection
Known conflicts
None. HackerRank does not enumerate desktop processes from the browser tab.
One Alt-combo per action.
Every workflow is a single keystroke. No mouse hunting mid-round, no menu pop-ups for the proctor to log.
| Combo | Action | Note |
|---|---|---|
Alt + Enter | Solve — read problem, propose solution | — |
Alt + 1 | Debug — re-read state, fix the failing test | — |
Alt + 2 | Optimize — re-read once more, cut complexity | — |
Alt + Move / Alt + W A S D | Reposition the overlay | HackerRank does not consume Alt-modified keys, so no collision in full-screen mode. |
Alt + ' | Audio-priority solve from the latest accepted speech buffer | — |
What HackerRank's proctor actually does.
Tab-switch / focus-loss tracking
HackerRank polls `document.visibilityState` and `window.onblur` on a ~250ms cadence in full-screen mode. Triggers a recruiter-side flag if focus leaves the editor for more than ~100ms.
The overlay never grabs focus. Hotkey input is captured at the kernel keyboard hook, not by stealing focus from the browser. The HackerRank tab keeps focus the entire time.
Full-screen mode flag
HackerRank uses the Fullscreen API and reports any exit to the recruiter dashboard. The flag fires if you switch monitors or apps.
No exit-fullscreen needed — FaangCoder paints over the same monitor the browser is on. The browser never sees a fullscreenchange event.
MOSS-style plagiarism similarity
Submitted code is scanned against a corpus of known solutions using a Winnowing-style fingerprint (Stanford MOSS approach). Triggers a "similar to N candidates" badge in the recruiter view.
The model output is not verbatim from any external corpus — Solve mode generates against your prompt template, not pasted from a stored solution.
Webcam analysis (optional, recruiter-enabled)
Some HackerRank rounds enable webcam recording. Reviewed post-hoc by the recruiter, not analyzed in real time.
The overlay is not visible to the webcam by definition. Voice mode (Alt + ') keeps the response audible without an on-screen read.
What the recruiter sees.
HackerRank does not run its own screen-share — recruiters pair the round with Zoom, Google Meet, or Microsoft Teams. FaangCoder is excluded from those streams via the Windows display pipeline — the kernel-level overlay strip removes the surface from the capture path before any DXGI duplication or GDI BitBlt can see it. Verified across Zoom 5.16+, Meet, and Teams as of May 2026.
Test the screen-share behavior yourself on the /proctor page — same detection vectors a real proctor uses, runs in the browser, no install.
HackerRank questions, answered.
Does HackerRank detect FaangCoder?
Will HackerRank's tab-switch detector catch the overlay grabbing focus?
Does the screen-share invite (Zoom / Meet / Teams) show FaangCoder?
What about HackerRank Skills Verification (the recorded asynchronous test)?
What if HackerRank ships a kernel-level detector?
Field guides for the rest of the loop.
FaangCoder on CodeSignal
home of the IQ Score and Certified Evaluations — keystroke biometrics, LLM-output similarity, full-screen mode
FaangCoder on CoderPad
the live-coding editor used by ~70% of FAANG-tier loops — Sandbox, AI-content detection, paste tracking, and the Enterprise tier that pairs with Amazon Chime
FaangCoder on LeetCode
practice surface + LeetCode for Companies (proctored take-home assessments) + timed contests with submission similarity
Pre-flight your HackerRank round in 60 seconds.
$399 lifetime ($199/mo monthly option). Install in 60 seconds, prove it on /proctor before the round.