How to Prevent Interview Coding Assignment Leaks

Coding assignments are a core tool for evaluating candidates in technical interviews. But these assignments are increasingly being leaked online, creating a serious problem. A quick search on GitHub surfaces take-home assignments and model solutions from well-known companies.

The Reality of Assignment Leaks

The Company Side

• Reusing the same assignment means candidates can prepare answers in advance
• Replacing leaked assignments costs the engineering team time and resources
• Leaks mean interview outcomes are determined by information access, not ability

The Candidate Side

• Your submitted code could appear online, disadvantaging you in future interviews
• Posting assignment results on a public GitHub may violate an NDA
• There are cases where companies use submitted code without authorization

Assignment Protection Strategies for Companies

Distribute Assignments via Password-Protected Links

Instead of attaching assignments to emails or sharing via Google Docs, use password-protected links.

Workflow:

1. Write the assignment brief as a secret memo
2. Set a unique password for each candidate
3. Set an expiration time (e.g., 72 hours)
4. Send the link and password to the candidate through separate channels

Advantages:

Traditional Method	Password-Protected Link
Email attachment -> can be forwarded endlessly	Cannot be viewed without password
Google Docs -> anyone with the link can access	Auto-deletes after expiration
Internal system -> complex infrastructure needed	No additional system required

Create Unique Variations Per Candidate

Even with the same topic, giving each candidate a slightly different version allows you to trace the source if a leak occurs.

Candidate A: "Library Management System" + search feature
Candidate B: "Library Management System" + checkout feature
Candidate C: "Library Management System" + recommendation feature

Time-Limited Access

Restricting the viewing window makes it harder for candidates to seek external help.

Assignment Type	Recommended Time Limit
Simple coding problem	24 hours
Project-based assignment	72 hours
System design problem	48 hours
Code review assignment	24 hours

Submission Protection Strategies for Candidates

Do Not Post on Public GitHub

Posting interview assignments to a public GitHub repository causes multiple problems.

• It may violate the company's NDA
• Other candidates can copy your code
• The company may blacklist you

Use Private Repositories

If you want to keep a record of your work, always use a private repository.

# Create a private repository
gh repo create interview-task --private

# Or change an existing repo to private
gh repo edit --visibility private

Submit via Password-Protected Link

You can also use a secret memo when submitting your assignment to the company.

1. Write the repository URL or submission notes in a secret memo
2. Set a password
3. Send the link and password separately to the interviewer
4. Revoke repository access after the interview process ends

LOCK.PUB Usage Scenarios

Scenario 1: Company Distributing an Assignment

1. HR creates a secret memo on LOCK.PUB with assignment details and submission instructions
2. Sets a password and 72-hour expiration
3. Sends the link via email
4. Delivers the password via phone or text message
5. Assignment auto-expires after 72 hours

Scenario 2: Candidate Submitting an Assignment

1. Candidate uploads code to a private GitHub repository
2. Creates a secret memo with the repo URL and access instructions
3. Sets a password and 7-day expiration
4. Sends the link and password to the interviewer
5. Revokes repository access after the interview concludes

Scenario 3: Company Sharing Access Credentials

When providing dev environment credentials or test accounts to a candidate.

1. Write server URL, account, and password in a secret memo
2. Set expiration equal to the assignment period
3. Deactivate the test account after the interview

Best Practices for Both Sides

For Companies

• Rotate assignments regularly (at least quarterly)
• Include unique identifiers per candidate
• State NDA requirements clearly in the assignment
• Distribute via tools with expiration features
• Revoke access after evaluation is complete

For Candidates

• Never post interview assignments to public repositories
• If you signed an NDA, comply with it strictly
• Limit the access period when submitting
• Deactivate shared links after the interview ends
• Confirm who owns the intellectual property of the submission

The Future of Interview Assignments

As leak problems grow, many companies are exploring alternatives.

Method	Pros	Cons
Live coding	Real-time evaluation, impossible to leak	Stressful environment, limited scope
Time-limited assignment	Minimizes leak window	Time pressure
Pair programming	Closest to real work	Requires interviewer time
Password-protected distribution	Easy to implement	Requires password sharing

Wrapping Up

Interview assignment leaks hurt both companies and candidates. Companies cannot evaluate fairly, and diligent candidates are disadvantaged. Using password protection and expiration features can significantly improve assignment security.

Start managing your interview assignments securely with a secret memo today.

Create a Secret Memo ->