AI Overlay for Codility CodeLive and CodeCheck on Mac
If you are interviewing at Microsoft, Intel, Tesla, or a few hundred other engineering shops, you will probably meet Codility. Their CodeCheck async tests and CodeLive interview product both run in Chrome and rely on browser-level behavioral signals rather than any kind of OS hook.
Codility was founded in 2009 by Greg Jakacki and Tomasz Walen in Warsaw, with current HQ in San Francisco and offices in London. Their CodeCheck product is an asynchronous coding test while CodeLive is a real-time coding interview where you share a workspace with a human engineer. Both run entirely inside a browser tab. The proctoring layer classifies behavior into four buckets: copy-paste tracking, tab switching, time spent per task, and copying the task description into something like ChatGPT.
Key points
- Codility detects tab focus changes with a millisecond timestamp but cannot see what you switched to. The overlay never causes the test tab to lose focus.
- Paste detection fires on Cmd-V into the editor. Type from the overlay instead of pasting and the paste counter stays at zero.
- Webcam snapshots are stored for 30 days and reviewed by the hiring team, not by Codility.
- CodeCheck async tests permit Google for syntax lookups; CodeLive interviews typically do not.
- There is no Codility desktop app on Mac. The entire stack runs in Chrome or Safari and uses standard browser APIs.
How it works
┌── macOS host ─────────────────────────────────┐ │ ┌── Safari/Chrome ─────────────┐ │ │ │ ┌── proctoring extension ─┐ │ │ │ │ │ Browser screen-capture │ │ ← reads │ │ │ │ → exam recording │ │ visible │ │ │ └─────────────────────────┘ │ pixels │ │ └──────────────────────────────┘ │ │ │ │ ┌── LDBypass overlay ──────────┐ ← rendered │ │ │ ChatGPT / Claude / Ollama │ excluded │ │ └──────────────────────────────┘ from cap │ └───────────────────────────────────────────────┘
Compatibility on Mac
| macOS 14 Sonoma+ | Yes (required for window-privacy API) | ✓ |
| Apple Silicon (M1/M2/M3/M4) | Native arm64 build | ✓ |
| Intel Macs (2019+) | Universal binary supported | ✓ |
| Codility CodeCheck (async) | Browser-only, capture honors window privacy | ✓ |
| Codility CodeLive (interview) | WebRTC screen-share, same exclusion | ✓ |
| Codility behavioral proctoring | Tab and paste signals are independent of overlay | ✓ |
Common questions
Will Codility flag me for looking away during a CodeLive interview?
Looking-away detection compares your eye position to the webcam frame. Reading the overlay keeps your gaze on the laptop screen.
Is using AI on a CodeCheck test against the rules?
Most employers prohibit external assistance on the actual test. We recommend treating async tests as practice.
Can the human interviewer in CodeLive see the overlay through their screen-share view?
No. CodeLive piggybacks on getDisplayMedia. macOS excludes private windows from that API at the OS level.
Does Codility record my screen for the full session?
CodeLive records the shared workspace and webcam. CodeCheck does not record the screen at all.
Will Codility detect that I am running a second app on my Mac?
Codility cannot enumerate macOS processes from a browser tab.