Voice interviews: talk it through, like the real thing
Get graded before the real interview.
Run a full mock round of coding, system design, AI-assisted or behavioral, phase by phase. Then read a write-up of what you covered, what you missed and how an interviewer would score it.
249 questions: the Blind 75 plus 75 more coding, 41 system design, 22 AI-assisted and 36 behavioral. Pay once, practice for good.
System design, mid-level
Design a URL shortener
- Reads dominate, about 100:1, so redirects need to be fast and highly available.good: read/write ratio
- ~40 new links a second, ~4K redirects a second, about 600 GB a year.numbers ✓
- POST /links returns a 7-char code; GET /{code} answers with a 302.why 302, not 301?
- Codes are base62 of a counter, so there are no collisions to check.
- Redis in front of the key-value store for hot codes.what if Redis dies? −7
Lean hire. Spend your deep dive on failure handling.
Try one right now. No account.
Answer the opening of a real question and see how it's marked. Same rubric as the full round, graded in your browser in a second.
Design a URL shortener like bit.ly. In one answer: what are the requirements, roughly how big is it (100M new links a month, 100:1 reads to writes), and how would you generate the short codes and keep redirects up?
Your grade goes here.
Marked against the real rubric for this question, the same one the full round uses.
Then watch a whole round play out.
This is the real interview room running a sample session. Pick a round type: the interviewer asks, pushes back when something's missing, and the write-up lands when you finish.
System design · mid-level · Sample session
Design a URL shortener
- Requirements
- Estimates
- API + data
- High-level
- Deep dive
Your interviewer · senior engineer, runs the round like a real loop
Waiting for you
InterviewerLet's design a URL shortener like bit.ly. Before any boxes, what does it need to do?
notes.md
- Questions
- 249
- Round types
- 4
- After every round
- Graded write-up
How it works
- 1
Pick a round
Coding, system design, AI-assisted or behavioral, at your level. Each one runs on the clock, like the real thing.
- 2
Answer like it's real
The interviewer talks and you answer out loud, like a phone screen. Code in Python, JavaScript, Java, C++ or Go with tests that run; draw the architecture on a whiteboard. Skip the failure handling and you'll be asked about it.
- 3
See exactly what cost you
Every rubric point scored, a fix for every miss, a model outline, and a dashboard of what you keep missing.
Your last 10 rounds
Sample data
What you keep missing
- Failure handling in deep dives4 of 6 rounds
- Stating Big-O before coding3 of 7 rounds
- Numbers in behavioral results2 of 3 rounds
Focus next: Design a distributed cache (practices failure handling)
Practice the whole onsite, not just LeetCode.
A typical loop is four rounds in one day. MockDojo has all four, each with its own rubric.
- 10:00Coding The Blind 75 plus the rest of the most-practised 150. Graded on clarifying questions, the optimal approach, working code, testing and Big-O.150 questions
- 11:00System design The most-asked designs, from URL shorteners to Uber and Google Docs. Requirements, estimates, data model, a deep dive, trade-offs.41 questions
- 13:00AI-assisted newReading AI-written code, catching its bugs, directing the tool, proving the fix.22 questions
- 14:00Behavioral A clear situation, what you did yourself, a measurable result, what you learned.36 questions
Some interviews now hand you an AI assistant.
Google is piloting a coding round it calls “human-led, AI-assisted”, in which interviewers grade prompting, checking the AI's output and debugging. Meta has tested AI-enabled coding interviews. Anthropic, Shopify and Canva allow AI tools in some rounds.
The skill being tested isn't typing prompts. It's judgment: reading code you didn't write, spotting what's wrong, proving it, and knowing what to check by hand. That's what the AI-assisted rounds practice.
- Review the AI's pull requestai-assisted coding, 30 min, free
- Direct an AI assistantai fluency, 30 min
- Design an AI support assistantai system design, 40 min
- Read unfamiliar codecode comprehension, 20 min
- When the AI got it wrongai fluency, behavioral, 15 min, free
- Design LLM inference servingai engineering, system design, 45 min
- and 16 more AI-assisted questions
Sources: Google's AI-assisted coding pilot (May 2026); Meta testing AI-enabled interviews (July 2025); Which companies allow AI in interviews (2026 tracker). Policies vary by team, so check with your recruiter.
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Browse every question, see how each round runs and what it's graded on, and read a sample write-up. Interviews need Lifetime or Pro.
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Anything else? Ask us.
Who is interviewing me?
A structured interviewer built from how real loops run. Each question has the phases an interviewer walks you through. It asks a follow-up when you skip something they'd look for, gives a hint only when you ask, and moves on when you've covered a phase. It isn't a chatbot improvising, so the same answer always gets the same grade.
How is the grade worked out?
Every question has a weighted rubric with the points an interviewer would write up. Your answers and your notes or code are checked against it, and thin answers score low no matter which words they use. Treat it as a practice signal, not a prediction of an offer.
What's an AI-assisted round?
A round where you work with AI-written code or direct an AI tool, and you're graded on judgment: reading the code, finding what's wrong, proving it with a test, and knowing what to check by hand. Some companies now run rounds like this; the links in that section have the details.
Is there an AI interviewer?
Yes, on paid plans. It asks free-form follow-ups like a real interviewer. Pro includes AI interviews every month, Lifetime includes 20, and you can add 10 more for $19 any time. The structured interviewer is always unlimited.
Is there a free trial?
You can browse every question for free and see exactly how each one is run and graded, plus a sample write-up. Interviews themselves are part of Lifetime or Pro, so everyone practicing gets the full experience.
Which plan should I pick?
If you're starting a job search, the 3-month plan. If your loop is in two weeks, monthly. If you'd rather never think about a subscription again, Lifetime.
Can I cancel?
Yes, anytime from Settings, under Manage billing. You keep Pro until the end of the period you paid for. Lifetime is a single payment, so there's nothing to cancel.