How to interview at McKinsey, BCG and Bain in the age of AI

AI now does much of the analysis at the three firms. Here is how they work today, who they hire and how the interview is changing, with every figure linked to its source. Then five skills to practise, each with a worked interview question.

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  1. McKinsey went from 3,000 AI agents to about 20,000 in 18 months
  2. All three firms now put AI in every consultant’s hands
  3. AI and tech work is now over 40% of BCG’s revenue
  4. The firms still hire juniors, but the mix is changing
  5. McKinsey has started testing candidates on a case worked with its own AI
  6. Five skills AI can’t do for you, each with a worked question

McKinsey went from 3,000 AI agents to about 20,000 in 18 months

McKinsey’s global managing partner, Bob Sternfels, gave the figures in January 2026: about 40,000 people, now working beside a fleet of AI agents that grew by more than 500% in a year and a half. His forecast: “In another 18 months I think every employee will be enabled by one or more agents” (Fortune, Jan 14, 2026, opens the source).

He was just as clear about what the agents can’t do: “There isn't truth in AI models; there isn't judgment” (Fortune, Jan 14, 2026, opens the source). The Next Web later reported the same CES figure as about 25,000 agents.

Exhibit 1: McKinsey’s people and AI agentsEach square is 1,000
People
~40,000
AI agents, mid-2024
3,000
AI agents, January 2026
~20,000

Source: Fortune, Jan 14, 2026

All three firms now put AI in every consultant’s hands

McKinsey built its own assistant, Lilli. Bain built Sage, an in-house platform that helps consultants find past case insights, and gives every employee ChatGPT Enterprise. BCG says its people “now use AI tools daily” (City AM, on BCG's 2025 results, Apr 23, 2026, opens the source).

In practice that means the first draft of the research, the slide and the spreadsheet is increasingly made with AI. What the consultant adds is the question, the check and the call.

Exhibit 2: What each firm has said about its AI tools
FirmToolOn the record
McKinseyLilliMore than 75% of employees use it monthly
BCGAI tools firmwideEmployees now use AI tools daily
BainSage, plus ChatGPT Enterprise for every employee19,000+ custom GPTs built by Bain teams

Sources: The Next Web, May 24, 2026; City AM, on BCG's 2025 results, Apr 23, 2026; Bain & Company careers blog, Aug 21, 2025

AI and tech work is now over 40% of BCG’s revenue

BCG grew revenue 7% to $14.4 billion in 2025 and said its AI- and tech-focused services “now represent over 40 per cent of BCG’s total revenue” (City AM, on BCG's 2025 results, Apr 23, 2026, opens the source), driven by 25% growth in AI services. At Bain, “nearly one-third of Bain's client work involves AI and technology” (Bain & Company careers blog, Aug 21, 2025, opens the source).

For a candidate, that changes what a case is likely to be about: more clients asking where AI fits in their business, and what it is worth.

Exhibit 3: Share of the firm’s work tied to AI and technologyAs each firm reports it
BCG, 2025 revenue
40%+
Bain, client work (2025)
~⅓

Two different measures: BCG reports a share of revenue, Bain a share of client work.

Sources: City AM, on BCG's 2025 results, Apr 23, 2026; Bain & Company careers blog, Aug 21, 2025

The firms still hire juniors, but the mix is changing

Exhibit 4: What each firm has said about hiring
FirmDirectionOn the record
McKinseySmaller, broader profilesWorkforce down 10%+ from 2023 to 2025, entry level most affected
BCGGrowing, more technicalHeadcount up 500 to 33,500 in 2025
BainGrowingHires in every role need “technical curiosity”

Sources: The Next Web, May 24, 2026; City AM, on BCG's 2025 results, Apr 23, 2026; Bain & Company, Aug 3, 2026

McKinsey has started testing candidates on a case worked with its own AI

According to the Financial Times, McKinsey candidates “analyzed a case with the help of Lilli” (CIO, reporting the Financial Times, Jan 15, 2026, opens the source) and were assessed on how well they formed their questions, read the answers and put them in the client’s context. McKinsey declined to comment on the report.

The rules elsewhere are clear. McKinsey welcomes AI to refine a résumé and practise, but not in assessments or interview answers. In April 2026 it launched a free AI practice tool for its quantitative case.

Exhibit 5: Where AI shows up in McKinsey’s hiring process
  1. ApplyAI is welcome to refine résumés and practise interview questions.
  2. PractiseA free AI practice tool for the quantitative case, with unlimited attempts.
  3. AssessmentAI during assessments or to write interview answers is not permitted.
  4. InterviewReported trial: work a case with Lilli; judged on your questions and judgment.

Sources: Fortune, Jan 14, 2026; The Next Web, May 24, 2026; CIO, reporting the Financial Times, Jan 15, 2026

Five skills AI can’t do for you, each with a worked question

What the firms’ leaders say they still look for, in their own words. Click any quote to open its source, then work the question.

Frame the problem, and aim high

The first minutes of a case test whether you can pick the right question. Models are good at answering the question they’re given. Picking it, and deciding how ambitious the answer should be, is still a person’s job. Asked at CES what the models can’t do, McKinsey’s global managing partner answered:

“What can the models not do? Aspire. Set the right aspiration.” (opens the source)

Bob Sternfels, global managing partner, McKinsey ·CES 2026, Jan 8, 2026 · at 42:04

In an interview, that means restating the client’s goal, asking the one question that could change your plan, and saying what a great outcome would look like before you reach for a framework.

A gym chain wants to double its profit in three years. How would you approach it?Worked question · Profitability · Structuring · 10 minTry it: structure a profit question, step by step

Make the call, and stand behind it

Analysis is getting cheap. Deciding what it means for a client, and saying so to their face, isn’t. Ron Kermisch, who leads talent acquisition at Bain, puts it plainly:

“AI can draw a market map for you, but it can't review that market map with a client to understand the nuances and make sure it makes sense. And it can't help a client make changes to his or her business.” (opens the source)

Ron Kermisch, global head of talent acquisition, Bain ·Bain’s Beyond the Bio podcast, Jul 31, 2026 · at 20:52

Faster analysis raises the bar rather than lowering it. Anna Mattsson, a senior partner at McKinsey, says “what that actually means is that we require judgment, much better judgment” (Anna Mattsson, Business Insider (YouTube), opens the source). In a case, judgment is a recommendation made before you have every number: the answer first, the reasons, the main risk, and what would change your mind.

The partner has two minutes. Should the fund buy Corvus Software?Worked question · Recommendation · Judgment · 8 minTry it: give a two-minute recommendation

Check the numbers yourself

Recruiters now expect candidates to be fluent with AI tools. BCG’s CEO, Christoph Schweizer, told the Wall Street Journal: “We are blown away about the junior talent we can hire. They are so AI native, they use these tools as if the world had never existed without them.” (Christoph Schweizer, The Wall Street Journal (licensed reprint on bcg.com), opens the source) The basics haven’t moved, though. Alicia Pittman, BCG’s global people chair:

“The fundamentals remain constant: curiosity, judgment, resilience and teamwork. Those traits matter even more in an AI-enabled environment.” (opens the source)

Alicia Pittman, global people chair, BCG ·Financial Times, Feb 26, 2026

A study of 758 BCG consultants shows what can happen when people stop checking. On a business problem the AI handled badly, the researchers found that “for a task outside the frontier, subjects using AI were 19 percentage points less likely to produce correct solutions” (Dell’Acqua et al., Organization Science, opens the source). Reading an exhibit is the interview version of that check: the units, the base and what’s missing, before you trust the headline.

Which portfolio holds the most bad loans, and what should the review do about it?Worked question · Exhibit · Marimekko · 6 minTry it: read an exhibit the way an interviewer wants

Learn fast, and learn from people

Leaders at the firms say they hire for how fast you learn, not for what you already know about AI. Christin Owings, who leads BCG’s London office, told the FT: “We also continue to hire people who might have almost zero knowledge of AI when they join, because we hire people who have deep curiosity.” (Christin Owings, Financial Times, opens the source) Tamar Dor-Ner, Bain’s Americas regional managing partner, says “it's probably even more important that you're built to keep up” (Tamar Dor-Ner, Bain’s Beyond the Bio podcast, opens the source).

Much of that learning still happens person to person. Bain’s CEO, Christophe De Vusser:

“You learn by seeing the best in action and if the best see you in action, they will coach you every single day. That apprenticeship you can't replace.” (opens the source)

Christophe De Vusser, worldwide managing partner and CEO, Bain ·Bain on LinkedIn, May 8, 2026 · at 0:07

A market you’ve never sized is a small test of this. There’s no pattern to match, only reasoning you can explain out loud and correct as you go.

How many public EV charging points will a city of one million people need by 2030?Worked question · Market sizing · First principles · 8 minTry it: size a market from first principles

Recover, and be yourself

McKinsey’s leader has said the firm used to screen differently. Bob Sternfels told HBR’s IdeaCast that it had been “too focused on, “Did you have perfect marks?” versus, “Did you have a setback and recover?”” (Bob Sternfels, HBR IdeaCast, opens the source) The firm also wants the person, not the script. Marie Christine Padberg, who co-leads McKinsey’s global talent attraction:

“We don't want over-prepared people. We want to really get to the depth of a person's skills and capabilities through a connection and a conversation, and we don't want over-rehearsed people” (opens the source)

Marie Christine Padberg, global talent attraction co-leader, McKinsey ·Business Insider, May 2026

The experience interview tests both. Pick a real setback, say what you changed, and tell it the way you would to a colleague rather than reciting it.

“Tell me about a time you failed.”Worked question · Experience interview · Resilience · 6 minTry it: answer “Tell me about a time you failed”

Sources

Rules on using AI in interviews differ by firm and change often. Check each firm’s current guidance before you start.

Figures

  1. Fortune, “McKinsey wants liberal arts majors and AI agents”, Jan 14, 2026. Open the source.
  2. CIO, reporting the Financial Times, “McKinsey begins testing candidates with an AI assistant”, Jan 15, 2026. Open the source.
  3. City AM, on BCG's 2025 results, “AI-focused services make up 40 per cent of BCG's 2025 revenue”, Apr 23, 2026. Open the source.
  4. The Next Web, “McKinsey launches an AI practice tool for its case interview”, May 24, 2026. Open the source.
  5. Bain & Company careers blog, “Five ways Bain is leading with AI”, Aug 21, 2025. Open the source.
  6. Bain & Company, “How is AI changing the way Bain hires consultants?”, Aug 3, 2026. Open the source.

Quotes

  1. Bob Sternfels, CES 2026, Jan 8, 2026. Open the source.
  2. Ron Kermisch, Bain’s Beyond the Bio podcast, Jul 31, 2026. Open the source. Quoted from our own transcription of the official audio; two separate speech-to-text models agree on every quoted word.
  3. Anna Mattsson, Business Insider (YouTube), Aug 5, 2026. Open the source. Quoted from our own transcription of the official audio; two separate speech-to-text models agree on every quoted word.
  4. Christoph Schweizer, The Wall Street Journal (licensed reprint on bcg.com), 2026. Open the source.
  5. Alicia Pittman, Financial Times, Feb 26, 2026. Open the source.
  6. Dell’Acqua et al., Organization Science, Mar 11, 2026. Open the source.
  7. Christin Owings, Financial Times, Feb 26, 2026. Open the source.
  8. Tamar Dor-Ner, Bain’s Beyond the Bio podcast, Jun 29, 2026. Open the source. Quoted from our own transcription of the official audio; two separate speech-to-text models agree on every quoted word.
  9. Christophe De Vusser, Bain on LinkedIn, May 8, 2026. Open the source. Quoted from our own transcription of the official audio; two separate speech-to-text models agree on every quoted word.
  10. Bob Sternfels, HBR IdeaCast, Jan 6, 2026. Open the source.
  11. Marie Christine Padberg, Business Insider, May 2026. Open the source.

Quotes are verbatim from the linked pages as they read on Oct 13, 2026. Video links open at the quoted moment. Roles are as described in the source.