LEK Consulting Case Interview: Complete Preparation Guide

L.E.K. Consulting stands apart from MBB firms by combining deep industry specialization with strategy-focused engagements — over 60% of their work concentrates in life sciences, healthcare, and private equity sectors. With roughly 2,200 professionals across 21 global offices, LEK offers a smaller, more intimate environment while maintaining high-caliber project work. The interview process reflects this boutique positioning: it tests both analytical rigor and your ability to synthesize complex information under pressure through a distinctive written case format.

LEK Interview Process Overview

LEK’s recruiting process has evolved to include digital pre-screening, making it more accessible to candidates from diverse backgrounds. Based on our experience working with candidates, the full process typically spans 4-6 weeks from application to offer.

The digital assessment is not used in every office — some regions skip directly to first-round interviews. If your application includes the assessment, expect to complete it within 5-7 days of submitting your resume.

The LEK Digital Assessment

LEK uses a HireVue-powered digital assessment to screen candidates efficiently before investing in-person interview time. Unlike McKinsey’s Solve game or BCG’s Casey chatbot, LEK’s assessment focuses on cognitive games rather than case-based scenarios.

The assessment includes three game types:

Mental Math Games

You receive a target number and an operator (+, -, ×, or ÷), then select two numbers from a list that produce the target when combined. Speed and accuracy both matter — the games adapt in difficulty based on your performance.

Pattern Memorization

A complex shape appears with certain sections highlighted. After viewing, you must identify which sections were highlighted from memory. This tests working memory and attention to detail.

Spatial Reasoning (Jigsaw-Style)

Move pieces within a fixed area to complete a task — similar to pipe-connection puzzles where you create a continuous path. This evaluates problem-solving approach and logic under time constraints.

Preparation tips for the digital assessment:

• Take the assessment when you’re mentally fresh — scheduling it for your peak alertness hours improves performance
• Ensure stable internet and a distraction-free environment
• Read each game’s instructions fully before starting; assumptions can cost points
• Practice brain-training games that involve quick mental arithmetic and pattern recognition in the days leading up
• The assessment has no “wrong answers” per se, but your pattern of responses is compared against successful LEK consultants

The LEK Written Case: What Makes It Unique

LEK’s written case is the signature element of their final round — and where many well-prepared candidates stumble because they’ve only practiced verbal case interviews. Based on candidate feedback, approximately 70% of final-round candidates face a written case.

Written Case Format

You receive a packet of roughly 30 slides containing a mix of:

• Client background and strategic context
• Market data and competitive analysis
• Financial statements and operational metrics
• Customer research and qualitative insights

You then have 60 minutes to analyze this material and complete approximately 7 partially-filled outline slides that LEK provides. These might include:

• Blank graphs or tables you need to populate
• Headers with no supporting content
• Calculation worksheets requiring your analysis

After preparation, you deliver a 30-minute presentation to a panel: ~20 minutes presenting your findings and recommendation, followed by ~10 minutes of Q&A where interviewers challenge your conclusions.

Written Case Strategy

The biggest mistake candidates make is diving into the data immediately. Instead, follow this approach:

First 5 minutes: Frame the problem

• Read the outline slides LEK provides — they reveal the expected structure
• Identify the core business question you’re solving
• Write a hypothesis you can test against the data

Minutes 5-40: Targeted analysis

• Work backward from the outline slides — what data do you need to complete each one?
• Skip information that doesn’t directly support your slides
• Rough calculations are fine; precision matters less than directional accuracy
• Document key numbers on the appropriate outline slides as you find them

Minutes 40-55: Build your narrative

• Ensure your slides tell a logical story: Situation → Analysis → Recommendation → Risks
• Practice saying what you’ll present for each slide
• Prepare for obvious pushback questions

Final 5 minutes: Review

• Check your math for major errors
• Ensure your recommendation is clearly stated
• Have a backup position ready if challenged

LEK Case Interview Content

LEK cases lean heavily toward strategy and quantitative analysis. In our analysis of LEK-style cases, the firm emphasizes market sizing, M&A due diligence, and growth strategy more than operational or organizational cases.

Because LEK has deep expertise in healthcare and life sciences, expect cases in these industries if you’re interviewing for offices with strong healthcare practices (Boston, London, Chicago). Private equity-related cases appear frequently given LEK’s substantial PE due diligence work.

Practice with M&A cases and market entry cases to align with LEK’s case distribution. For industry context, explore our healthcare cases collection.

Behavioral / Fit Interview

LEK’s behavioral interviews are conducted separately from cases — you won’t be asked fit questions in the middle of case analysis. Interviewers focus on:

• Teamwork and collaboration: LEK emphasizes its close-knit culture; show you work well in small, intense teams
• Analytical curiosity: Demonstrate genuine interest in solving complex business problems
• Communication skills: Can you explain complex ideas clearly and persuasively?
• Industry interest: If you’re targeting their healthcare or PE practice, articulate why

Prepare 4-5 STAR stories that highlight quantified achievements. LEK interviewers appreciate specificity — saying “I improved efficiency by 30%” beats “I made things better.”

Preparation Timeline

A focused 6-8 week preparation plan works well for LEK interviews:

Critical preparation elements for LEK specifically:

1. Written case practice: Few candidates practice this format — it’s a major differentiator. Time yourself with large data packets and practice distilling information under pressure.

2. Presentation skills: The written case presentation is where you win or lose the final round. Practice presenting to a timer and recording yourself.

3. Healthcare/Life Sciences context: If targeting these practices, understand basic industry dynamics — drug development timelines, payer structures, regulatory pathways.

4. Mental math speed: LEK cases frequently require quick calculations during the verbal portion. Use our mental math guide for daily practice.

Key Takeaways

• LEK’s interview process includes a unique HireVue digital assessment testing logic, pattern recognition, and numerical skills — practice brain-training games beforehand
• The written case is LEK’s signature final-round element: 60 minutes to analyze ~30 slides and complete outline slides, followed by a 30-minute presentation and Q&A
• LEK cases emphasize strategy and quantitative analysis — M&A, growth strategy, and market sizing cases are most common
• Healthcare, life sciences, and private equity contexts appear frequently; understand basic industry dynamics for your target practice
• Behavioral interviews are separate from cases and focus on teamwork, communication, and analytical curiosity
• LEK’s smaller firm size means interviewers assess culture fit carefully — demonstrate you’d thrive in an intimate, collaborative environment

Start practicing with LEK cases from our case library, or use the AI Mock Interview to simulate both verbal cases and written case scenarios with real-time feedback.