Mock coding and behavioral interviews, out loud.

A voice interviewer gives you a LeetCode-style problem or a behavioral question, asks the follow-ups a real one would, and scores you without inflating it.

Also: system design · resume grill · AI-assisted coding · AI fluency

Interviewing for an internship · a new-grad role · an experienced role

// the rounds

Five rounds, one interviewer.

Coding

1,100 problems in 8 languages.

Your code runs against test cases in the same window.

15 to 45 minutes, your choice.

Try it →
1def length_of_longest(s):
2 seen = {}
3 left = best = 0
4 for right, ch in enumerate(s):
5 if ch in seen:
6 left = seen[ch] + 1
7 seen[ch] = right
8 best = max(best, right - left + 1)
9 return best
Tests
PASS"abcabcbb" → 3
PASS"bbbbb" → 1
PASS"pwwkew" → 3
PASS"" → 0
FAIL"abba" → 2, got 3
PASS"dvdf" → 3
PLATO · What's the time complexity, and where would it break?

// the grader

A grader that doesn't inflate.

Every score is based on what you said, and Pro shows you the exact words.

Transcript · Contains Duplicate · 18:42
Plato

Before you write it: what should happen if the same value appears twice?

You

I think it should be fine. I’ll just code it and see.

Put off the question about duplicates
Plato

Okay. Talk me through it as you go.

You

So I loop, check the map, add to the map. Okay, that passes, I think I am done.

Called it done on the sample input
Overall—/ 10Borderline
Problem understanding—
Problem solving—
Code quality—
Communication—
Testing—

Hover a score to see the line behind it.

See full sample reports for all five tracks →

// try it

The assistant wrote this. Which line is wrong?

It should merge overlapping intervals. [[1,4],[4,5]] should come back as [[1,5]].

solution.py· written by the assistantclick a line

Plato: “Your assistant says it’s done. Before you run it, which line worries you?”

// how a week of prep goes

Interview date
October 202612 days to go
Your plan
Mon 12Coding
Wed 14AI-assisted
Fri 16Behavioral
Mon 19System design
Wed 21AI fluency
Thu 22 · Interview

// what you are probably using now

How it compares.

A problem site
A human mock interview
A general chatbot
Placed
Asks follow-ups out loud
—
✓
If you ask it to, in text
✓
Runs your code
✓
Sometimes
—
✓
Same rubric every session
—
Depends on the interviewer
—
✓
Cost of the tenth session
Free or a subscription
$170 to $300 each
Your chat subscription
$19 a month, or 3 free

Placed is for practicing the real thing. It doesn't sit in your live interview.

// pricing

Start free.

Free
$0
  • 3 mock interviews per month
  • All 5 interview tracks — coding, behavioral, system design, AI-assisted coding & AI fluency
  • Overall and per-skill scores
  • Top 2 things to fix after each interview
  • The full report for your first interview
  • Learn mode: 1 session a month with Plato as your tutor
  • Session history
  • Readiness score
  • Company tags on every problem
Start free
ProRecommended
$19a month
  • Unlimited mock interviews
  • Unlimited learn mode: work any problem with Plato as your tutor, who sees your code
  • Full report: why each skill scored what it did, with quotes from your interview
  • Reference solutions and model answers
  • Ask Plato about your score
  • Resume-tailored interviews — questions that reference your real background
  • Weakness-targeted drills — practice your lowest-scoring skills
  • Premium AI grading — feedback from our most capable model
  • Filter problems by company — Google, Meta, Stripe & more
  • Full session history & exports
  • Cancel anytime
Upgrade to Pro

// questions

You can start an interview without an account. A free account gets 3 scored interviews a month across all five tracks, with the full report for the first one and the scores and the top two things to fix after that, plus one learn mode session. Pro is $19 a month for unlimited interviews, unlimited learn mode, the full report, resume-tailored questions and drills on your weakest skills, or $119 a year, with 50% off for students.

Each criterion is scored 0 to 10 from what you actually did in the session, and the grader has to quote the moment each score is based on. A clean criterion scores 8 or 9, and 10 is possible. A minor slip, like one weak variable name, costs at most a point; a real gap, like never testing your code, costs 2 to 3; a wrong approach costs more. An answer that only sounds good scores 5 at most.

Yes. Most intern loops are one or two coding rounds and a behavioral round, and both are here. Filter the library to easy and medium problems. The grader scores against a full-time hiring bar, so expect lower numbers than you would get on a class assignment.

Python, JavaScript, TypeScript, Java, C++, Go, Rust and C#. Your code runs in all of them. Test cases are checked automatically in every language. In Java and C++ that covers the 98 problems verified for them so far; on the rest you run the code and read the output yourself.

No. Every round has a text box next to the microphone, and you can type any answer. The interviewer can also be muted. Talking is still worth practicing, because the real interview is spoken.

Audio from your microphone is sent to a speech-to-text service and turned into text. When you are signed in, your scores, reports, code and chat transcripts are saved to your account so they show up in History. As a guest, the transcript stays in your browser until you create an account. You can ask for your account and its data to be deleted at support@placed.dev.

A coding round where you are given an AI assistant and judged on how you use it: what you ask for, whether you check its output, and whether you catch its mistakes. Some companies have added it to their loops and others ban AI outright; placed.dev/ai-interview-policies lists which, with sources. Placed runs the round as its own track with its own rubric.

Yes, at any time from the Pricing page under Manage subscription. You keep Pro until the end of the billing period you paid for, then the account goes back to the free plan.

When is your interview?

Interviewing for
No account needed. Leave the date empty for a two-week plan.

No date yet? Start a round now.