2nd/10_Wiki/Topic_Programming/AI_and_ML/Case Interviews.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-case-interviews	Case Interviews (Consulting)	10_Wiki/Topics	verified	self	case interview consulting interview MBB MECE pyramid principle hypothesis-driven	none	B	0.88	applied	career consulting mbb case-interview mece problem-solving structured-thinking communication		2026-05-10	pending	language applicable_to career / soft skills Consulting Recruitment Structured Problem-Solving Strategic Communication

Case Interviews

📌 한 줄 통찰

"매 logical reasoning 의 stress test". 매 ambiguous business problem + 매 limited info + 매 30 min. 매 MBB (McKinsey, BCG, Bain) 의 hiring filter. 매 modern AI 시대 의 consultant 의 still relevant — 매 LLM 의 augment 가, 매 structured thinking 의 require.

📖 핵심

매 case 의 type

1. Profitability: 매 revenue / cost 의 분석.
2. Market sizing: 매 estimate.
3. Market entry: 매 strategic decision.
4. M&A: 매 acquisition.
5. New product: 매 launch decision.
6. Strategy: 매 broad.
7. Operations: 매 process improvement.

매 framework

MECE (Mutually Exclusive, Collectively Exhaustive)

• 매 bucket 의 overlap X.
• 매 exhaustive coverage.
• 매 무 missing.

Pyramid Principle (Minto)

1. 매 conclusion 먼저.
2. 매 supporting argument 의 grouping.
3. 매 facts.

5R (closing)

• Recap: 매 question.
• Recommend: 매 answer.
• Reasons: 매 supporting.
• Risk: 매 consideration.
• Retention (next step): 매 follow-up.

Hypothesis-driven

• 매 hypothesis 먼저.
• 매 test with data.
• 매 update or replace.

매 process

1. Listen + restate: 매 prompt 의 confirm.
2. Clarifying questions: 매 scope 의 narrow.
3. Structure (60 sec think): 매 framework.
4. Walk through: 매 plan 의 explain.
5. Analyze: 매 quantitative + qualitative.
6. Synthesize: 매 insight.
7. Recommend: 매 5R close.

매 evaluation criteria

• Structure: 매 MECE.
• Logic: 매 sound reasoning.
• Quantitative: 매 quick math.
• Communication: 매 clear.
• Insight: 매 non-trivial.
• Pressure: 매 calm.
• Adaptability: 매 framework 의 flex.

매 common framework

Profitability

• 매 Revenue (price × volume) - 매 Cost (fixed + variable).
• 매 segment-wise breakdown.

4P (Marketing)

• Product, Price, Place, Promotion.

5C

• Company, Customer, Competitor, Collaborator, Context.

Porter's 5 Forces

• 매 industry attractiveness.

Value Chain

• 매 inbound → operations → outbound → marketing → service.

→ 매 모든 의 mechanical 적용 X. 매 problem 의 fit.

매 modern (AI era)

• 매 LLM 의 framework / data 의 augment.
• 매 case 의 still 인간 의 final.
• 매 structured thinking 의 increasingly valuable.
• 매 AI 의 한계 (hallucination, judgment) 의 understand.

매 prep resource

• 매 "Case in Point" (Marc Cosentino).
• 매 "Case Interview Secrets" (Victor Cheng).
• 매 PrepLounge / Management Consulted (mock).
• 매 firm 의 own case prep.

매 anti-pattern

• 매 framework 의 force.
• 매 structure 없이 jump.
• 매 silent thinking.
• 매 panic on numbers.
• 매 ignore interviewer 의 hint.

💻 패턴 (응용)

Structured response template

[Listen + Restate]
"매 understand 의 sure 의 — [restatement of the question]. Right?"

[Clarify]
"Before structuring, may I ask:
1. What is the company's current state?
2. Are we looking at a specific market / time horizon?
3. How is success defined?"

[Structure (after 60 sec think)]
"I'd like to break this into [N] areas:
1. [Bucket 1]: [why this matters]
2. [Bucket 2]: ...
3. [Bucket 3]: ...

Let me start with [bucket 1] because [reasoning]."

[Analyze each bucket]

[Synthesize + 5R]
"To summarize:
- The question was [Recap].
- I recommend [Recommend].
- Because [Reasons 1-3].
- Risks include [Risk 1-2].
- Next steps would be [Retention]."

Profitability framework

Profit = Revenue - Cost

Revenue = Volume × Price
  Volume:
    Market size × Market share × Customer frequency
    By segment / channel / geography
  Price:
    By segment / channel
    Trend / mix shift

Cost = Fixed + Variable
  Fixed: rent, salaries, depreciation
  Variable: COGS (materials, labor), marketing, distribution
  By cost driver

Market sizing (Fermi estimation)

"How many tennis balls fit in a Boeing 747?"

1. Plane volume: ~875 cubic meters (interior, after subtracting walls/seats).
2. Tennis ball volume: ~0.0001 m³ (4πr³/3 with r=3.4cm).
3. Packing efficiency: ~70% (FCC packing).

= 875 / 0.0001 × 0.7 ≈ 6.1 million tennis balls.

Sanity check: 매 reasonable order of magnitude.

Mock interview prompt

MOCK_PROMPTS = [
    "Our client is a regional grocery chain. Profits dropped 15% last year. Why?",
    "Should our pharma client enter the African market?",
    "How would you size the global market for electric toothbrushes?",
    "A streaming service is losing subscribers. What would you investigate?",
    "Our manufacturing client has 30% scrap rate. How to reduce?",
]

def practice_session():
    import random
    prompt = random.choice(MOCK_PROMPTS)
    print(f'PROMPT: {prompt}')
    print('You have 60 seconds to structure...')
    # 매 record voice + 매 transcribe + 매 LLM critique

LLM-assisted prep

def case_critique(transcript):
    return llm.generate(f"""You are a McKinsey case interview coach. Evaluate this case response transcript on:

1. Structure (MECE? clear buckets?)
2. Logic (sound reasoning? cause-effect?)
3. Math (correct? clear?)
4. Communication (concise? confident?)
5. Insight (non-trivial conclusions?)

For each, give:
- Score 1-5
- Specific evidence from transcript
- One concrete improvement

Transcript:
{transcript}""")

Common math drill

- 매 Mental: 17 × 24 = ?
  Trick: (20-3)(24) = 480 - 72 = 408
  
- 매 Percentage: $4.5M is 36% of total revenue. What's revenue?
  $4.5 / 0.36 = $12.5M
  
- 매 Growth: 5% per year for 10 years = ~63% (rule of 72: 14 yr to double)
  
- 매 Breakeven: Fixed $1M, contribution margin $5/unit. Breakeven volume?
  1M / 5 = 200K units

🤔 결정 기준

상황	Framework
Profit declining	Profitability tree
Market entry	Market attractiveness + Capability fit
New product	4P + go-to-market
Pricing	Cost-based / value-based / competitor-based
Cost reduction	Cost driver decomposition
M&A	Strategic fit + financial + integration
Estimation	Top-down + bottom-up

기본값: 매 problem 의 listen + 매 framework 의 fit (force X).

🔗 Graph

• 부모: Problem_Solving
• 변형: MECE · Pyramid Principle · Hypothesis-Driven
• Adjacent: Articulateness · Be-Detailed · Beliefs · Bounded_Rationality

🤖 LLM 활용

언제: 매 consulting prep. 매 structured thinking exercise. 매 mock practice. 매 critique. 언제 X: 매 final interview substitute. 매 framework 의 mechanical 적용.

❌ 안티패턴

• Force framework: 매 problem 의 fit X.
• Silent thinking: 매 interviewer 의 see X.
• Skip structure: 매 jump 의 chaos.
• Ignore hint: 매 interviewer 의 lead 의 follow X.
• Panic on math: 매 estimate first.
• No 5R close: 매 hanging finish.
• Memorize 의 manual answer: 매 surface 의 lose.

🧪 검증 / 중복

• Verified (Cosentino "Case in Point", Cheng's "Case Interview Secrets", MBB own materials).
• 신뢰도 B.
• Related: Articulateness · Be-Detailed · Bounded_Rationality · Pyramid Principle.

🕓 Changelog

날짜	변경
2026-04-27	Auto-mapped
2026-05-08	Phase 1
2026-05-10	Manual cleanup — type + framework + 5R + 매 mock / critique / Fermi code