Run a realistic technical interview end to end. Six stages, an interviewer that pushes back, and a report that scores your reasoning, not just your output.
6
Stages
1
Combined report
3
Readiness bands
System Design
Stage 04 · Deep dive
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
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.
Technical questions you answer by speaking, typing, and coding, with follow-ups that dig in like a real interviewer.
Fix and build code against real tests while you think aloud. Ask the interviewer questions as you go.
Talk through a project you've built, then defend your decisions under follow-up questions.
Design a system on a canvas while you narrate, then defend your tradeoffs in a deep dive.
Read a teammate's pull request, comment line by line, and call the verdict. Scored on what you catch and how you say it.
Build a small feature with an AI assistant. Stay in control of the result, then get coached on your judgment.
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.
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.
How it runs
The interviewer asks a question from your focus area
You answer by voice, text, or code, whatever the question demands
Follow-ups dig into your answer like a real interviewer would
Difficulty adapts to how you're performing
What's scored
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.
How it runs
Read the ticket and the failing tests
Ask clarifying questions before you commit to an approach
Code against the real test suite while narrating your thinking
Defend your approach when the interviewer pushes back
What's scored
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.
How it runs
Introduce your project and what problem it solves
Walk through the architecture and key decisions
Defend your choices under deep follow-up questions
Own what you'd change and why
What's scored
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.
How it runs
Clarify requirements and constraints before you draw
Design the system on the canvas while narrating
Walk through data flow, scaling, and failure modes
Defend your tradeoffs in the deep dive
What's scored
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.
How it runs
Read the full diff before commenting
Leave line-by-line comments where it matters
Separate blocking issues from nitpicks
Call the verdict and justify it
What's scored
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.
How it runs
Read the feature spec and plan your approach
Direct the AI assistant with clear, scoped prompts
Review and verify everything before you keep it
Ship a result you can fully explain
What's scored
Pick the role you're preparing for, from backend to frontend to data.
Your interview draws from this focus plus the shared fundamentals every interviewer expects.
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.
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.
You know where you stand and exactly which stage is holding you back.
Performing at the level service company interviews actually demand.
Performance that places you at a product-ready level for an entry role.
The habits interviewers actually remember, tracked across every stage you run.
Finish a full sitting and earn a public Plaicer MockMonitor card with your overall score, percentile and sub-domain breakdown. Share it to LinkedIn in one click, or have an educator endorse it.
Answer out loud where it counts. Your speech is transcribed by your browser's built-in speech service; we store text transcripts, not audio.
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.
Free to start. The room is ready when you are.