McKinsey’s careers page says that for most client-facing roles, “you will participate in a personal experience interview, followed by a problem-solving interview.” The behavioral part comes first, and it isn’t a warm-up.
MBB is shorthand for McKinsey, BCG (Boston Consulting Group), and Bain. A behavioral interview asks how you actually acted in past situations: what you did, what you said, what happened. All three publish what they assess, and that language beats most prep advice.
This guide covers what each firm looks for, the questions to expect, how to build a story bank, and how to handle follow-ups.
Behavioral and case work usually sit in the same process, often in the same conversation. McKinsey pairs a personal experience interview with a problem-solving interview. BCG runs a skills interview before the case, then a team interview. Bain customizes by role: some candidates get a standalone behavioral interview, others get behavioral questions inside other interviews.
No firm publishes how long the segment runs or how much it counts, and prep-site figures don’t come from the firms. Ask your recruiter what your round includes.
Some form of fit interviews across industries appears in nearly every structured recruiting process, so this story work gets reused elsewhere.
Expectations scale with the candidate pool. A junior draws on student organizations, jobs, and class projects. If you’re a first-year MBA recruiting for consulting during an MBA program, the bar is professional impact: a decision you owned, a stakeholder you moved, a team you led.
McKinsey’s interviewing page tells candidates to “come prepared to discuss some important experiences in a detailed way, focusing on your specific role and describing the key actions that were critical to success.” It suggests bringing “two personal examples” of impact in each of four areas.
Those areas appear as clickable themes on the page, and the labels have been reworded over the years, so read the current tabs rather than a list from elsewhere. An international version of the same McKinsey page names personal impact (interacting effectively with people, “sometimes in challenging situations”), entrepreneurial drive, inclusive leadership, and problem-solving skills; candidate accounts also describe a theme framed around courageous change.
The PEI’s distinguishing feature is depth. Candidates typically report that the interviewer picks one story and stays there: what exactly you said, how the other person responded, what you would do differently. Two deep stories beat eight shallow ones.
McKinsey is explicit about AI. Practicing interview questions with it is “Encouraged,” while “Exaggerating or creating achievements that aren’t yours” and “Generating real-time answers during an interview” are “Not Allowed.”
BCG’s interview process page lists four steps: application, skills interview, case interview, and team interview. The skills interview is the behavioral one: “In this traditional interview, we will explore your experience, skills, and motivation for joining BCG; your chance to go beyond your resume.”
The page names five qualities interviewers look for: Integrity, Intellectual Curiosity, Creative Thinking, Collaborative Mindset, and Drive. Treat it as a checklist: one story per quality, plus a “why BCG” answer built on things you could only know from talking to people there.
Bain’s interviewing page says interviews are customized to the role, and that “some roles will include at least one behavioural interview, while other interviews may incorporate behavioural questions” about past experiences. Bain also gives “all candidates the same questions for each role to reduce bias.”
Bain says it looks for “curious problem-lovers” who are “intellectually curious, entrepreneurial, and who find challenges exciting,” and adds: “In all cases, we look for people who can explain why they want to join us specifically.” Formats vary by office, so ask your recruiter which interviews your round includes.
| Firm | Behavioral format (per the firm) | Qualities the firm names | Prep implication |
|---|---|---|---|
| McKinsey | Personal experience interview, then a problem-solving interview | Four themes: personal impact, entrepreneurial drive, inclusive leadership, problem-solving | Two deep examples per theme; expect drill-down |
| BCG | Skills interview before the case, plus a team interview | Integrity, Intellectual Curiosity, Creative Thinking, Collaborative Mindset, Drive | One story per quality; a specific “why BCG” |
| Bain | At least one behavioral interview in some roles; behavioral questions in others | “Curious problem-lovers” who can say why Bain specifically | Firm-specific motivation; team stories |
No firm publishes its question list. These are the kinds of questions candidates hear, grouped by the themes the firms name.
| Theme | Representative question | What a strong answer shows |
|---|---|---|
| Influence and personal impact | “Tell me about a time you changed the mind of someone who disagreed with you.” | The other side’s view; tailored persuasion |
| Drive and entrepreneurship | “Describe a goal you pursued that others thought wasn’t realistic.” | Ownership; creativity with few resources |
| Inclusive leadership | “Tell me about a time you got a group with clashing views to work well together.” | Quieter voices heard; conflict handled |
| Change and courage | “Tell me about a time you pushed for a change others resisted.” | Judgment and a considered risk |
| Integrity | “Describe a time you had to do the right thing when it was inconvenient.” | Clear values under inconvenience |
| Failure and learning | “Tell me about a time you failed. What did you do next?” | Honest ownership; a changed behavior |
| Motivation | “Why consulting, and why this firm specifically?” | Evidence from conversations |
| Background | “Walk me through your resume.” | One clear thread in 60 to 90 seconds |
STAR is the common structure: Situation (context in two sentences), Task (what you owned), Action (what you personally did), Result (what changed). Keep Situation and Task to about a quarter of the answer and spend the rest on Action. Most people do the opposite.
Two habits separate strong answers:
Expect these follow-ups:
Say you were treasurer of a student club that spent most of its budget on one annual gala, and wanted two smaller events instead.
Weak Action: “We looked at the budget, realized the gala wasn’t worth it, and convinced the board to change the plan.”
Stronger Action: “I pulled three years of spending and attendance and found the gala took most of the budget and drew a small share of our members. Two board members were attached to it, so I asked them before the vote what they most wanted to protect and built the proposal around that. Then I presented cost per attendee and proposed piloting one small event rather than scrapping the gala.”
Only the second survives “what exactly did you say?” For more patterns, work through answering “tell me about a time” questions.
Aim for six to eight stories, not twenty. Each good one covers two or three themes, enough to give every McKinsey theme two options and every BCG quality one. Build a matrix to see the gaps:
| Story | Influence / impact | Drive | Leadership / collaboration | Change / integrity |
|---|---|---|---|---|
| Club budget turnaround | Yes | Yes | Yes | |
| Internship data project | Yes | Yes | ||
| Team conflict on capstone | Yes | Yes |
An empty column is next week’s prep list. Your own resume bullets that point to stories are the fastest source: any bullet with a number behind it hides an Action.
If you’re an undergrad. Stories come from student organizations, part-time jobs, athletics, research, class projects, and family responsibilities. Scale is not the test: a 4,000clubbudgetanda4 million one get judged on what you noticed, what you decided, and who you persuaded. If your examples feel thin, revisit the campus leadership experiences where you made a call that could have gone badly.
If you’re an MBA student. Use pre-MBA work as the core and add one or two from business school, such as a club role or a study-team conflict. Team-based work still needs your role stated explicitly. Start in October alongside your resume: that is what building a story bank in your first semester buys you when invitations land. Check the MBA consulting interview calendar for how many weeks you have.
On “why consulting, why this firm.” This can’t be built from firm websites. It comes from coffee chats, office events, a specific practice area you can name, and a credible career story that makes consulting the logical next step.
The failures are predictable:
Case practice has a ceiling. Story preparation doesn’t, because the material is yours.
