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AI-Powered Case Interview Preparation

Master McKinsey, BCG, and Bain case interviews. Practice live with interactive partner-style simulations and receive instant, structured feedback on framework, math, and synthesis.

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preppartnr - AI-Powered Case Interview Preparation for MBB & Tech (McKinsey, BCG, Bain)

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A Free ChatGPT Prompt for Case Interview Practice

You don't need a paid tool to start. Paste this into ChatGPT (voice mode works too) and it'll run a structured mock case. Here's exactly what to paste, how to use it, and where it starts to fall short. Want Consistent Grading Instead? Try a Free AI Voice Mock Interview: Same idea, fixed rubric, tracks your weak spots across sessions.

The Prompt

Paste this at the start of a new chat, before you say anything else: You are a senior manager at a top-tier strategy consulting firm (McKinsey, BCG, or Bain) conducting a case interview. Your job is to test my structured problem-solving, not to teach me. Rules: 1. Give me one realistic case prompt (2-3 sentences) covering profitability, market entry, M&A, pricing, or market sizing — pick one at random and tell me which. 2. Wait for me to lay out my structure before giving me any data. Do not offer hints unless I explicitly ask. 3. Once I share my framework, push back on any part that isn't MECE, and ask me to defend my prioritization. 4. Feed me data only when I ask a clarifying question that would realistically surface it. If my question is vague, ask me to be more specific instead of answering. 5. Include at least one case-math calculation with realistic numbers I have to compute out loud. 6. At the end, ask me for a synthesized recommendation before giving feedback. 7. Grade me on four dimensions — structure, hypothesis-driven thinking, quantitative rigor, communication — each 1-5, with one specific example from this session per score. Stay in character as the interviewer until I say "end case" — don't break out to explain your reasoning mid-session.

How to Use It With Voice

Open the ChatGPT app, paste the prompt as your first message, then tap the headphones icon to switch to voice mode before you respond. Answer out loud — that's the part most candidates skip, and it's the part that actually matters.

Where This Breaks Down

The grading is the weak point. General models grade frameworks generously and rarely catch a genuinely non-MECE issue tree — you can walk away from a session feeling good about a structure that would've lost you the round. There's also no memory of what you got wrong last time, so nothing compounds session to session. That's the gap a purpose-built rubric is designed to close.

Frequently Asked Questions

Does this work with Claude or Grok instead of ChatGPT?

Yes — the prompt is model-agnostic. Voice mode setup differs slightly by app, but the instructions work the same way.

Is this actually as good as a paid tool?

It's a real starting point, not a replacement. It's free and unlimited, which makes it good for early volume. The tradeoff is inconsistent grading and no session memory — see the section above.

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