Top consulting firms are revolutionizing their legendary interview processes by integrating AI technology, marking a significant shift in how they evaluate candidates. McKinsey & Company, Boston Consulting Group (BCG), and other elite firms are now incorporating AI chatbots directly into their case interviews, fundamentally changing the decades-old recruitment playbook.
McKinsey has begun piloting Lilli, its proprietary internal chatbot, during candidate interviews. Lilli synthesizes the firm’s extensive proprietary research spanning 100 years, over 100,000 documents, and countless interviews. According to McKinsey Senior Partner Delphine Zurkiya, over 70% of the firm’s 45,000 employees now use Lilli, with active users engaging with the tool approximately 17 times per week. McKinsey analysts report using it for research, document summarization, data analysis, and brainstorming.
BCG has deployed its own AI interviewer called Casey, which conducts automated portions of the interview process. The chatbot presents candidates with case questions featuring more ambiguity than traditional in-person interviews. Ammon Jensen, an MBA candidate at Brigham Young University who recently accepted a summer internship at BCG, experienced Casey firsthand with a market-sizing exercise around a DoorDash competitor. He noted that unlike human interviewers who provide subtle feedback, Casey maintains complete neutrality, making it harder for candidates to gauge their performance.
Stephen Turban, a former McKinsey analyst who now helps students prepare for consulting interviews through Wall Street Guide, observed that Lilli appears in later interview rounds, often catching candidates off guard. “The biggest reaction is a little bit of a lack of preparation,” Turban explained, noting that the AI sometimes provides information that’s intentionally vague or incomplete to test problem-solving abilities under ambiguity.
The integration reflects a broader transformation in consulting work itself. These firms are shifting from pure advisory services toward building, implementing, and maintaining AI tools for clients, requiring candidates who understand AI nuances and can leverage the technology effectively.
However, there are strict limits on candidate AI use. BCG’s Dallas office has stopped reviewing cover letters due to ChatGPT making them too easy to generate. Marc Cosentino, author of the definitive consulting interview guide “Case in Point,” reported that some candidates have been permanently blacklisted for using unauthorized AI during Zoom interviews. Interviewers quickly detect such attempts, immediately terminate interviews, and share information across firms.
Key Quotes
The biggest reaction is a little bit of a lack of preparation. It seems like the AI is created to give information that’s not 100% correct or vague. So, it’s a test of how well students can solve problems with a certain level of ambiguity.
Stephen Turban, former McKinsey analyst and founder of Wall Street Guide, explains how Lilli surprises candidates and tests their ability to work with imperfect AI-generated information—a skill increasingly critical in real consulting work.
It’s really hard to get an interview, but once you’ve got an interview, they really want you to succeed. Casey, however, is more neutral.
Ammon Jensen, MBA candidate at Brigham Young University who accepted a BCG summer internship, describes the psychological difference between human and AI interviewers, highlighting how AI removes the supportive feedback candidates traditionally relied upon.
Some people have already gotten in trouble using AI during case interviews. The interviewers caught on almost immediately, wrapped up the interview, and told the candidates they would not be considered in the future. Word gets around.
Marc Cosentino, author of ‘Case in Point,’ reveals that consulting firms are permanently blacklisting candidates who use unauthorized AI tools during interviews, demonstrating strict boundaries around appropriate AI use despite the firms’ own AI integration.
Over 70% of the firm’s 45,000 employees now use the tool, and those who use it do so about 17 times a week.
McKinsey Senior Partner Delphine Zurkiya provides concrete metrics on Lilli adoption, demonstrating that AI has become deeply embedded in daily consulting work, making AI proficiency essential for new hires.
Our Take
The consulting industry’s AI interview revolution represents a fascinating case study in how professional services are adapting to technological disruption. McKinsey and BCG aren’t just testing candidates on AI—they’re fundamentally redefining what consulting competency means. The irony is striking: firms are using AI to evaluate candidates while simultaneously policing unauthorized AI use, creating a complex new ethical landscape.
This development also reveals an important truth about AI’s workplace integration: it’s not replacing human judgment but changing what skills matter. The ability to work with ambiguous, imperfect AI outputs—extracting signal from noise—is becoming as valuable as traditional analytical skills. For aspiring consultants, the message is clear: AI fluency is no longer optional. The broader implication extends beyond consulting: as AI tools proliferate across industries, professionals everywhere will need to demonstrate they can collaborate effectively with AI systems while maintaining ethical boundaries.
Why This Matters
This development signals a fundamental transformation in how elite professional services firms evaluate talent and conduct business. The integration of AI into McKinsey and BCG’s interview processes isn’t merely a technological upgrade—it reflects the consulting industry’s wholesale pivot toward AI implementation and advisory services.
As these firms transition from traditional strategy consulting to building and maintaining AI systems for clients, they need employees who can work seamlessly with AI tools. The interview changes serve as both a screening mechanism and a preview of actual job requirements. Candidates must now demonstrate not just analytical prowess, but AI fluency and the ability to extract insights from ambiguous, AI-generated information.
This shift has broader implications for professional services and white-collar work generally. If the most prestigious consulting firms are making AI proficiency a core competency, other industries will likely follow suit. The move also highlights an emerging paradox: while firms embrace AI for efficiency, they’re cracking down on candidates using the same tools inappropriately, establishing new ethical boundaries around AI use in professional contexts. For the thousands of MBA students and professionals aspiring to join these firms annually, AI literacy has transformed from optional to essential.
Related Stories
- PwC Hosts ‘Prompting Parties’ to Train Employees on AI Usage
- Goldman Sachs Hires Google’s Melissa Goldman as Tech Head for AI Push
- Business Leaders Share Top 3 AI Workforce Predictions for 2025
- The Future of Work in an AI World
- CEOs Express Insecurity About AI Strategy and Implementation
Source: https://www.businessinsider.com/mckinsey-interview-case-study-ai-test-bcg-2026-1