Interviewer-led
The interviewer sets each question and moves you on.
- You control
- How well you answer each step
- Watch for
- Linking each answer to the goal
Interviewer-led vs candidate-led cases, one case run both ways
In an interviewer-led case, the interviewer asks a series of set questions and moves you from one to the next. In a candidate-led case, you get some initial facts and are expected to lead: choose the structure, ask for data and decide what to look at next. Stanford's ADC Consulting Club says McKinsey primarily uses the interviewer-led format, and Bain, BCG and most others the candidate-led one. We build Soreno, an AI voice interview practice app. Candidate-led cases are hard to practice alone, so start with our free profitability case with no sign-up, where you ask for the data yourself.
Updated
- Interviewer-led
- A series of set questions
- Primarily McKinsey, per a Stanford club
- Candidate-led
- You drive the case
- Bain, BCG and most others, per a Stanford club
- Same skills
- Structure, math, synthesis
- Both formats test them
- Worked case
- One gym chain, two formats
- Invented by us, every number shown
What is the difference?
The interview guide of Stanford's ADC Consulting Club describes two formats. In the interviewer-led one, the interviewer asks a series of discrete questions. In the interviewee-led one, the interviewer gives some initial information and the candidate is expected to lead the conversation. The guide adds that either way you may need to draw a framework, form a hypothesis, read charts, calculate and defend a recommendation.
Candidate-led
You choose where to look and ask for the data.
- You control
- The order and the next step
- Watch for
- Getting lost in one branch
One case, interviewer-led (ours)4 questions
Northline Gyms, an invented chain of 40 gyms, has seen profit fall since last year. The interviewer asks set questions in order. Every number is invented by Soreno for practice.
Question 1
"How would you structure this?"
You give a profit tree: members times fee for revenue, and costs per gym. The interviewer then moves on, whether or not you'd have chosen to.
Question 2
"Here is the data. What happened to revenue?"
Members per gym fell from 1,000 to 900 at $50 a month, so yearly revenue fell from $24 million to $21.6 million.
Question 3
"Costs are flat. What does that mean for profit?"
With $18.2 million of yearly cost, profit fell from $5.8 million to $3.4 million, a drop of $2.4 million. All of it comes from the 10% fall in members.
Question 4
"What would you recommend?"
Find out why members leave before cutting costs, starting with the gyms that lost the most. Link it back: the whole drop is members.
The same case, candidate-led (ours)4 moves
Now you're handed the prompt and nothing else. You decide what to ask for.
Your move 1
Structure, then a hypothesis
"Profit is revenue minus cost. I'd like to start with revenue, since gym costs are mostly fixed. Can I see members and fees for both years?"
Your move 2
Read it and say what it means
"Members per gym are down 10% and fees are flat, so revenue fell by $2.4 million. Before I go further, are costs flat too?"
Your move 3
Close a branch and choose the next
"Costs are flat, so the whole drop is members. Each gym needs 760 members to cover its costs, so they still make money, but less. Next I'd like to know why members leave: is there churn data by gym?"
Your move 4
Synthesize without being asked
"So far: the drop is all membership, costs aren't the problem, and the next step is finding which gyms and which members are leaving."
How to tell which one you're in (ours)In the first minute
Interviewer-led signs
A specific question and data up front
The prompt ends with a direct question ("How would you structure this?") and the interviewer hands you exhibits before you ask.
Candidate-led signs
A broad prompt and silence
You get a goal and a few facts, then the interviewer waits. Data comes only when you ask for it.
If unsure
Ask
"Would you like me to lay out how I'd approach this, or do you have a first question for me?" is a fair thing to say.
From Stanford ADC Consulting Club: interview resources, McKinsey: interviewing and BCG: case interview preparation.
What both formats test
The firms' own prep pages describe what they look for without splitting it by format. In our experience the difference is only who decides what comes next.
A structure that fits this problem
McKinsey asks for tailored solutions rather than standard frameworks. Kearney's Netherlands page says not to force a solution to fit a standard framework.
Step-by-step reasoning
BCG asks you to structure your approach, ask thoughtful questions, analyze data, do quick calculations and identify the most important factors.
Working with the interviewer
Oliver Wyman says to think of the interviewer as your client, who wants you to solve the problem and can help. Kearney also casts the interviewer as a client offering initial facts.
A hypothesis you test
Kearney's Netherlands careers page tells candidates to test their hypothesis with more questions and fine-tune the solution based on the answers.
From McKinsey: interviewing, BCG: case interview preparation, Kearney: crack the case and Oliver Wyman: interview preparation.
8 cases to practice in both formats
Soreno's own questions. Do each one twice: once with a friend asking set questions, once leading it yourself. Under each, what to listen for.
Profit and cost
The easiest to run both ways.
A grocery chain's profits are down 20%. What happened?
Led by you: split revenue and cost before asking for anything. Led by them: link each answer to the 20%. Practice it, see a model answer
An airline is carrying more passengers but making less money. Why?
Shows per-passenger revenue and cost side by side, whichever format. Practice it, see a model answer
A streaming service's churn has doubled. What would you look at?
Candidate-led: say which customers first. Interviewer-led: keep the churn rate as the thread. Practice it, see a model answer
A retailer needs to cut costs by 10%. Where should it look?
Rank cost lines by size before going deep on one. Practice it, see a model answer
Growth and entry
Where leading the case matters most.
A gym chain wants to double revenue in five years. How?
Candidate-led: propose the options and pick which to size first. Practice it, see a model answer
A coffee chain is thinking about entering India. Should it?
Interviewer-led: expect a market sizing question in the middle. Answer it and tie it back. Practice it, see a model answer
Should a manufacturer build a second factory?
Decide early what would make the answer yes, then test it. Practice it, see a model answer
The CEO walks in. What's your recommendation?
The close is the same in both formats: answer first. Practice it, see a model answer
Mistakes in each format
Each format has its own traps. These are the ones we see most.
Interviewer-led: answering only the question
Each answer should end with what it means for the client's goal. The interviewer moves you on, but scores the link.
Interviewer-led: a long structure
You'll be redirected anyway. Give a clear first layer, then go where you're asked.
Candidate-led: waiting to be told
Silence is your cue to choose the next step and ask for data.
Candidate-led: staying in a dead branch
When the data rules a branch out, say so and move to the next most likely one. Stanford's ADC Consulting Club tells people giving a case to let the candidate make mistakes rather than correct them at once, so don't count on being pulled out.
Both: no recommendation
Whoever leads, end with a clear answer, the reason, a risk and a next step.
Lead a case out loud
Soreno's AI interviewer runs full cases by voice, hands you data only when you ask for it and scores how you drove the case. Start your free week.
Questions people ask
What is an interviewer-led case?
One where the interviewer asks a series of set questions and moves you from one to the next. Stanford's ADC Consulting Club says McKinsey primarily uses it.
What is a candidate-led case?
One where you get some initial information and are expected to lead: choose the structure, ask for data and decide the next step. Stanford's ADC Consulting Club says Bain, BCG and most others use it.
Does McKinsey use interviewer-led cases?
Stanford's ADC Consulting Club says so. McKinsey's own page calls its case interview the Problem-Solving Interview and doesn't use the term interviewer-led.
Which format is harder?
Neither, in our experience. Interviewer-led cases move fast and test each step. Candidate-led cases test whether you can choose the next step yourself.
Do I prepare differently for each?
The skills are the same: structure, math, reading data and a recommendation. Practice leading cases yourself, since that's harder to rehearse alone.
Can I ask which format it is?
Yes. Asking whether the interviewer wants your approach first or has a first question is reasonable.
What if a case mixes both formats?
In our experience many do: you lead the structure, then the interviewer steers you to a chart or a calculation. Treat each handoff as a cue to answer, then link the result back to the goal.
Is BCG candidate-led?
Stanford's ADC Consulting Club puts BCG with Bain and most others in the candidate-led group. BCG's own prep page asks you to work through the problem step by step: structure your approach, ask thoughtful questions and analyze data.