Mock Technical Interview

Practice a mock technical interview
like it's the real thing.

Sit a full technical interview from start to finish, with an AI interviewer that listens to your answers and follows up on them. Choose from six stages covering questions, live coding, system design, code review and more. At the end you get a written report that scores how you reasoned and communicated, not simply whether your code ran.

6

Stages

1

Combined report

3

Readiness bands

System Design

Stage 04 · Deep dive

Live transcript

Interviewer

You picked a queue in front of the ingest service. What happens when a consumer falls behind?

You

Lag grows but writes stay safe. I'd alert on consumer lag and scale the group before the retention window becomes the risk...

Interviewer

Transcribing…

Interview questions for every track you're placing in.

Java · Python · JavaScript · TypeScript · C++

Node JS · React · Next JS · Angular · Vue

Spring Boot · Django · SQL · DBMS · REST APIs

More coming soon

/ THE STAGES

Six rooms. One interview.

Pick one stage to drill it, or stack several to run back-to-back like the real thing, with one combined report at the end.

01
Stage 01

Interview Q&A

The interviewer asks technical questions from your chosen focus area, and you answer however the question calls for it: speaking out loud, typing, or dropping into a code editor. Every answer you give shapes the next follow-up, so a thin answer gets probed and a strong one gets pushed further.

SpeakTypeCodeAdaptive follow-ups
"Answer out loud where you can, that's what gets scored in real rooms."
02
Stage 02

Live Coding

You are handed broken or unfinished code and a real test suite, and you fix or build it while talking through your reasoning. You can ask the interviewer clarifying questions at any point, exactly as you would in a real pairing session.

Real testsThink aloudAsk questions
"Think aloud while you work, the interviewer is listening."
03
Stage 03

Project Deep Dive

You walk the interviewer through a project you have actually built: what it does, how it is put together, and why you made the calls you made. Then the follow-ups begin, and surface-level familiarity gets exposed quickly.

Your projectYour decisionsDeep follow-ups
"Pick the project you know inside out."
04
Stage 04

System Design

You get a design prompt with real constraints and a canvas to draw on. You clarify the requirements first, then design the system while narrating each choice, before defending your scaling and failure-mode decisions in a deep dive.

Design canvasNarrate liveDefend tradeoffs
"Clarify before you draw."
05
Stage 05

Code Review

A teammate's pull request lands on your desk. You read the diff, leave line-by-line comments, and decide whether to approve it or request changes. You are scored on the bugs and risks you catch, and on how constructively you raise them.

Line commentsCall the verdictTone matters
"Read first, comment second."
06
Stage 06

AI Feature Build

You build a small feature with an AI assistant beside you, the way most teams now work. The assistant helps, but you decide what actually ships, and afterwards you are coached on what you accepted, what you rejected, and what you verified first.

AI assistantStay in controlJudgment scored
"The assistant helps, you decide."
/ INSIDE EACH STAGE

What happens in every room.

Each stage runs like its own interview room, with its own format, its own flow, and its own scoring. Here's exactly what you walk into.

Stage 01

Interview Q&A

The interviewer asks real technical questions drawn from your chosen focus plus the shared fundamentals every interviewer expects. You answer the way you would in the room: speaking out loud, typing when it fits, and dropping into a code editor when a question calls for it.

Nothing is scripted. Every answer you give shapes the next follow-up, so a shallow answer gets probed and a strong answer gets pushed further. It's the closest thing to sitting across from an interviewer who actually listens.

"Answer out loud where you can, that's what gets scored in real rooms."
01

How it runs

1

The interviewer asks a question from your focus area

2

You answer by voice, text, or code, whatever the question demands

3

Follow-ups dig into your answer like a real interviewer would

4

Difficulty adapts to how you're performing

What's scored

Technical accuracyDepth under probingCommunication
Stage 02

Live Coding

You get working-but-broken or incomplete code and a real test suite. Your job is to fix it or build it out while thinking aloud, because the interviewer is listening to your reasoning, not just watching the tests go green.

You can ask the interviewer clarifying questions at any point, exactly like a real pairing session. Silent coding that happens to pass scores lower than clear reasoning that shows how you got there.

"Think aloud while you work, the interviewer is listening."
02

How it runs

1

Read the ticket and the failing tests

2

Ask clarifying questions before you commit to an approach

3

Code against the real test suite while narrating your thinking

4

Defend your approach when the interviewer pushes back

What's scored

CorrectnessApproach & reasoningThinking aloud
Stage 03

Project Deep Dive

You bring a project you've actually built and walk the interviewer through it: what it does, how it's put together, and why you made the calls you made. Then the follow-ups start.

The interviewer probes your architecture, your tradeoffs, and the decisions you'd make differently today. Surface-level familiarity gets exposed fast, which is exactly why this stage exists.

"Pick the project you know inside out."
03

How it runs

1

Introduce your project and what problem it solves

2

Walk through the architecture and key decisions

3

Defend your choices under deep follow-up questions

4

Own what you'd change and why

What's scored

Ownership & depthHonest tradeoffsDecision defense
Stage 04

System Design

You get a design prompt with real constraints and a canvas to design on. You clarify requirements first, then draw the system while narrating every choice out loud.

Once the design is on the canvas, the deep dive begins: scaling, failure modes, bottlenecks, and the tradeoffs behind every box you drew. A diagram you can't defend is just a picture.

"Clarify before you draw."
04

How it runs

1

Clarify requirements and constraints before you draw

2

Design the system on the canvas while narrating

3

Walk through data flow, scaling, and failure modes

4

Defend your tradeoffs in the deep dive

What's scored

Requirements clarificationDesign soundnessTradeoff defense
Stage 05

Code Review

A teammate's pull request lands on your desk. You read the diff, leave line-by-line comments, and call the verdict: approve or request changes.

You're scored on what you catch, from real bugs to subtle risks, and on how you say it. A correct comment delivered badly costs you in real teams, and it costs you here too.

"Read first, comment second."
05

How it runs

1

Read the full diff before commenting

2

Leave line-by-line comments where it matters

3

Separate blocking issues from nitpicks

4

Call the verdict and justify it

What's scored

What you catchComment qualityTone & verdict
Stage 06

AI Feature Build

You build a small feature with an AI assistant at your side, the way modern teams actually work. The assistant helps, but you stay in control of what ships.

Afterwards you get coached on your judgment: what you accepted, what you rejected, what you verified before trusting it. Blindly shipping AI output is exactly what this stage is built to catch.

"The assistant helps, you decide."
06

How it runs

1

Read the feature spec and plan your approach

2

Direct the AI assistant with clear, scoped prompts

3

Review and verify everything before you keep it

4

Ship a result you can fully explain

What's scored

Judgment on AI outputVerification habitsFinal result quality
/ HOW IT WORKS

Build the interview you're about to face.

Step 01

Choose your path

Start by telling us which role you are preparing for, whether that is backend, frontend, data or another track. Your interview is drawn from the areas that role is actually assessed on.

Step 02

Choose your focus

Narrow things down to the specific area you want to be tested on. Your interview pulls questions from that focus, plus the shared fundamentals every interviewer expects you to know regardless of specialism.

Step 03

Build your interview

Choose a single stage if you want to drill one weakness, or stack several to run back-to-back the way a real interview loop works. Stack them and you get one combined report covering the whole sitting rather than separate scores.

/ SCORING

Know exactly where you stand.

Every stage is scored on named dimensions with published anchors, then rolled into a readiness band recruiters understand. Cross-stage skills are tracked across everything you run.

Developing

Below 55

You are still building towards interview standard, and the report tells you precisely which stage is costing you the most so you know where to put your practice time.

Service-ready

55+

You are performing at the standard service and consultancy interviews actually ask for, and the report shows which areas would need lifting to reach product-company level.

Product-ready

72+

You are performing at the standard product companies expect from an entry-level engineer, across both your technical answers and the way you communicate them.

Cross-stage skills

The habits interviewers actually remember, tracked across every stage you run.

CommunicationQuestion-askingIndependenceDepth under probing

A credential you can share

Finish a full sitting and earn a Plaicer Verified card: a public page carrying your readiness level and the role you sat it for, plus your overall score, your percentile and a breakdown by sub-domain. Share it to LinkedIn in one click, or have an educator endorse it.

Speak like the real room

Answer out loud where it counts. Your speech is transcribed by your browser's built-in speech service; we store text transcripts, not audio.

/ YOUR COACH

Meet Paige.

Paige reads your whole interview history, spots your focus areas, and works on them with you between sittings. Ask her what to focus on next, where you're weakest, or how to lift your system design stage. She coaches you; the interviewer stays in the room.

Your first interview sets your baseline.

The room is ready when you are.

Start Mock Technical Interview
/ ALSO ON PLAICER

Practice a real DSA online assessment before the one that counts.

Before a company interviews you, most of them send a timed coding test first, and that is where the majority of candidates are filtered out. The DSA round is that test: four formats matched to real online assessments, hidden tests that only run on submission, and coaching on where your time actually went.

Four assessment formats from a 45-minute two-problem screen up to a 90-minute four-problem round.

Solve in Python, Java, C++ or JavaScript, with every problem verified in your language before you see it.

Scored on correctness, time management, edge-case discipline and code quality, then coached on each problem.

/ QUESTIONS

Mock interview questions

What languages do you cover in the interview questions?

Java, Python, JavaScript, TypeScript, C++ and Node JS are covered today. Your Interview Q&A and Live Coding stages run in the language you choose, and every sitting also draws the fundamentals interviewers expect: SQL, DBMS and REST APIs. More languages are being added.

Do you cover framework interview questions like React or Spring Boot?

Yes. React, Next JS, Angular and Vue are covered on the frontend side, with Spring Boot and Django on the backend. Pick your framework track and the interviewer draws questions from it alongside the core language, the same way a real placement interview mixes both.

What is a mock technical interview?

It is a full practice run of the interview a company would actually put you through, sat end to end rather than read about. An AI interviewer asks you questions, listens to your answers, and follows up on what you said. You speak, type and code your way through it, and at the end you get a written report on how you performed.

What are the six stages?

Interview Q&A covers technical questions with adaptive follow-ups. Live Coding gives you broken or unfinished code and a real test suite. Project Deep Dive has you defend a project you built yourself. System Design gives you a canvas and a design prompt. Code Review puts a teammate's pull request in front of you. AI Feature Build has you ship a small feature alongside an AI assistant while staying in control of the result.

Do I have to do all six stages at once?

No. Run a single stage if you want to drill one specific weakness, or stack several to run back-to-back the way a real interview loop works. Stack them and you get one combined report covering the whole sitting instead of separate scores.

Do I need to speak out loud?

For most stages, yes, and it is the point. Interviewers score how you explain your reasoning as much as what you produce, so silent work that happens to be correct scores lower than clear reasoning that shows how you got there. You can still type or drop into a code editor whenever a question calls for it.

How long does an interview take?

It depends on how many stages you stack. A single stage is a short sitting; a full six-stage loop takes considerably longer and is closer to what a real onsite feels like. You choose the shape when you build the interview.

Do I need a project of my own?

For the Project Deep Dive stage, yes. Bring something you have actually built, because the follow-ups go into your architecture, your tradeoffs and what you would do differently now. Surface-level familiarity with someone else's project gets exposed quickly. The other five stages need nothing from you in advance.

How am I scored?

Each stage is scored on its own criteria, and every stage also scores the skills that cut across all of them: communication, question-asking, independence and depth under probing. You get written coaching on each stage rather than a bare number.

What are readiness bands?

Three bands that translate your score into something useful. Developing means you are still building towards interview standard and the report names which stage is costing you most. Service-ready means you are performing at the level service and consultancy interviews ask for. Product-ready means you are at the standard product companies expect from an entry-level engineer.

Can I retake an interview?

Yes. Every interview you sit is kept with its scores and feedback, so you can see which parts are improving across attempts and which are not moving.

How is this different from practising with a friend?

A friend cannot easily keep pushing when your answer is thin, and will rarely tell you honestly that your communication was the weak part. The interviewer here adapts to your answers, probes shallow ones, and the report separates your technical accuracy from how well you explained it, which is usually the more useful signal.