Cheating in coding interviews: how it happens and how teams catch it

Coding rounds felt the change first. For years, a well-known problem, a shared editor and a camera were enough. Now a tool can read the problem off the screen and show a working solution in a window the interviewer never sees. This post covers how it happens, how common it is, why interviewers miss it, and what helps.

How people cheat in coding interviews

Five ways come up again and again.

• Screen-reading AI overlays. Interview Coder bills itself as "The No. 1 Undetectable AI For Interviews" and says its "Overlay remains hidden when sharing your screen". It lists HackerRank, CoderPad and Codility among its platforms, and Monthly Pro is $299 a month as of November 6, 2026. TechCrunch reported that the tool "is now part of their San Francisco-based startup Cluely", and that its co-founder "says he was able to snag an internship with Amazon using" it.
• A second device or notes off screen. Among assessments CodeSignal flagged in 2025, 35% "involved frequent off-screen referencing during the session".
• Someone else takes the test. CodeSignal lists "proxy test-taking" among the attempts it sees. See proxy interviews.
• Known or leaked questions. CodeSignal found that 15% of flagged assessments showed "elevated similarity to known answers or leaked content".
• Help from someone off camera, typing or speaking answers the camera does not show. See how people cheat in remote interviews for room helpers and earpieces.

How common it is

CodeSignal, which runs coding assessments, reports that "cheating and fraud attempt rates" on its proctored assessments rose "from 16 percent in 2024 to 35 percent" in 2025. For entry-level roles the rise was "from 15 percent to 40 percent", and the rate was "48 percent in Asia-Pacific compared to 27 percent in North America". These are the vendor's own figures, and it does not give a sample size.

Proctoring changes scores, too. CodeSignal says unproctored tests showed "score increases more than 4X larger than proctored ones". Among flagged assessments, 23% "showed unusually linear typing patterns". For survey numbers across interview types, see interview integrity statistics.

Why interviewers miss it

In an interviewing.io experiment published January 31, 2024, candidates used ChatGPT in mock technical interviews. Across 32 usable interviews, "not a single interviewer mentioned concerns about any of the candidates cheating!" The sample was small, and the interviews had audio but no video.

Two things explain it. First, the help is hidden. Overlay windows can be left out of screen capture; on Windows such a window "is displayed only on a monitor. Everywhere else, the window does not appear at all." The shared editor looks normal. Second, well-known questions are easy for AI. In the same experiment, pass rates were:

interviewing.io's conclusion was blunt: "companies need to start asking custom questions immediately".

How teams catch it in live coding interviews

• Custom questions. A question the internet has not seen is harder for a tool to answer, as the pass rates above show.
• "Why" follow-ups. Ask the candidate to explain a line, change a constraint, or say what they would test next. Their reasoning is the signal, not the finished code.
• Playback and alerts. CoderPad alerts interviewers when a candidate "Pastes code from an external source" or "Leaves the IDE (e.g., tab-switching)", and "Every pad records a complete timeline of the session." CoderPad adds that alerts "are most effective when paired with active interviewer response".
• Platform checks for tests. HackerRank says its plagiarism model "repeatedly detects ChatGPT-generated solutions, even when those results are typed in manually", and claimed "93% accuracy" in 2023 without defining the metric. What each platform offers is in can HackerRank detect cheating.
• An in-person round. Google's CEO said it is bringing back "at least one round of in-person interviews for people" to "make sure" candidates know "the fundamentals". McKinsey asks hiring managers to "schedule at least one in-person meeting with potential recruits before extending an offer".
• A check on the candidate's computer. The overlay runs there, so that is where a check has to look.

When AI is allowed on purpose

Some companies now invite AI in. Canva wrote in June 2025: "we now expect Backend, Machine Learning and Frontend engineering candidates to use AI tools like Copilot, Cursor, and Claude during our technical interviews". Its piloted "AI-Assisted Coding" interview replaces its Computer Science Fundamentals screen for backend and frontend roles. Meta planned to "allow some coding job candidates to use an AI assistant during the interview process", 404 Media reported in July 2025, and Hello Interview reports the rollout began in October 2025.

Allowing AI moves the risk rather than removing it. When AI is part of the round, what matters is that the person on the call is the person you will hire, and that rounds without AI stay that way. A hidden helper in a no-AI round, or a stand-in in any round, is still the problem.

A short policy for coding rounds

1. For each round, decide whether AI is allowed, and which tools.
2. Tell candidates at the start, in writing, and ask them to confirm.
3. Use custom or modified questions, and follow up on the candidate's own choices.
4. Review playback and paste alerts after take-home tests and live pads.
5. Confirm that the same person is on every round.
6. Treat any flag as a reason to ask, not a verdict.

Where Verified Call fits

Verified Call looks for hidden AI tools: AI answer helpers like Cluely and Interview Coder that hide from screen sharing. It names hidden helpers in the panel. Verified Call never joins the call. It plugs into the calls you already run. Google Meet today, actively expanding to Zoom and Teams.

Our own testing: 4 free AI answer tools (Interview Coder, OpenCluely, Pluely and Cheating Daddy), each opened 30 times, plus 30 runs with no AI tool and 30 with everyday apps open. Each tool was found in 30 of 30 tries, with 0 of 30 false alarms with no AI tool open and 0 of 30 with everyday apps open (October 4, 2026). The details are on the Research page.