The L.E.K. interview process pairs one of the tougher numerical screens in strategy consulting with dense, commercial case interviews. L.E.K. Consulting is a global strategy firm with deep roots in London and Boston, best known for commercial due diligence, life sciences and healthcare, education, and transport work. That mix shows up directly in how the firm selects: numbers first, then judgment. This guide covers each stage and the preparation that pays off.
L.E.K. at a Glance
L.E.K. advises corporates and private equity funds on growth strategy, market assessment, and transactions. Due-diligence work under deal timelines is a large share of the business in many offices, which explains the firm's insistence on speed and accuracy with data. Teams are comparatively lean, and junior consultants get analytical ownership early.
For candidates, the practical consequence is simple: every stage of the process tests whether you can produce a defensible number quickly and say clearly what it means.
Stage 1: The Numerical Reasoning Test
After the CV screen, most candidates sit an online numerical and logical reasoning test before any interview. L.E.K. does not publish the specification, and details vary by office and intake, but recent candidate reports describe a consistent pattern:
- A proctored, multiple-choice test of roughly half an hour, commonly reported at around 18 questions, which works out to well under two minutes per question.
- No calculator. The arithmetic is school-level in content but unforgiving on speed: percentages, ratios, quick algebra, and data read from tables and charts.
- A mix of question families: fast computation, data interpretation, critical reasoning, and, in some versions, data-sufficiency style questions where you judge whether the information given is enough to answer.
- Difficulty that ramps up in the final stretch, so banking the early questions quickly matters.
Some intakes, notably for UK graduate roles, also report a separate verbal reasoning test. As always, your invitation email is the authority on what you will sit; prepare for what it names.
Preparation is mostly about restoring speed. Daily no-calculator drills on percentages and ratios, plus a few timed simulations to calibrate pacing, move the needle more than any amount of untimed practice.
Stage 2: Case Interviews, Often in a Super Day
Candidates who clear the test move to interviews. Several offices run these as a super day: first-round and second-round interviews compressed into a single day, with a pair of interviews in the morning and, for those who advance, another pair in the afternoon. Each interview typically runs about half an hour: a few fit questions, then a case.
L.E.K. cases reflect the client work. Expect market sizing, market attractiveness, and profitability prompts with a due-diligence flavour: is this market really growing, would you back this target, what would you need to believe for the deal to work. Interviewers push on the numbers, and mental math under observation is a constant. If that is a weak spot, drill it daily and practise market sizing until the mechanics are automatic.
The fit portion is short but real: why consulting, why L.E.K., and evidence that you know what due-diligence work actually involves. Candidates who can talk concretely about the firm's sectors stand out.
What L.E.K. Rewards
- Numerical confidence. Not advanced math, but clean, fast, correct arithmetic with the interviewer watching.
- Structured commercial logic. A case structure built from how the specific business makes money, not a recited template; see our case interview frameworks guide.
- Evidence discipline. Due-diligence thinking means saying what the data supports, what it does not, and what you would check next.
- Concise synthesis. Deal timelines are short; recommendations are expected to lead with the answer.
How to Prepare
- Weeks 1 to 2: the screen. No-calculator arithmetic daily, plus timed numerical test simulations until pacing under two minutes per question feels routine.
- Weeks 2 to 4: cases. Full cases with market sizing and profitability prompts, always with a hard synthesis at the end. Practise being pushed on your numbers without losing composure.
- Final week: the super day. Rehearse back-to-back interviews so stamina is not a surprise, and tighten fit answers on why L.E.K. specifically.
A structured case interview preparation plan helps sequence the work, and scored practice tells you whether your quantitative dimension is actually improving or just feeling better.
Sources & Further Reading
- L.E.K. Consulting, Official site: the firm's practices, offices, and recruiting pages.
- Glassdoor, L.E.K. interview reports: candidate-reported interview experiences and formats.
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