The McKinsey Solve is a 60-70 minute gamified online assessment that McKinsey uses to screen candidates before interviews. Most candidates complete two game-like modules — Sea Wolf (~30 minutes of microbe-selection ocean cleanup) and Redrock Study (~35 minutes of data analysis and report questions) — which measure problem-solving process: critical thinking, decision-making under uncertainty, and data interpretation. It replaced the McKinsey PST (Problem Solving Test) in 2020 and is typically required before interview rounds (coverage and format vary by region and intake year — confirm with your McKinsey recruiter).
For module-by-module strategy, scoring mechanics, and a prep plan, see the full McKinsey Solve prep guide. To feel the format yourself, you can practice the Sea Wolf module free or run a timed Red Rock data-analysis session.
| Duration | 60-70 minutes total |
| Format | 2 gamified scenarios (order varies) |
| Where | Online, proctored via webcam |
| Pass Rate | Top 20-30% of candidates (estimated) |
| Retake Policy | Once per application cycle (typically 2 years) |
| Former Name | Imbellus, PSG (Problem Solving Game) |
Note: McKinsey retired the Ecosystem Building scenario globally in mid-2025. Candidates today see Sea Wolf and Redrock Study. Older prep materials that describe "picking 8 species from 39" are referencing the retired format — a food-chain building task where each species reportedly had to sit inside its terrain ranges (elevation, temperature) and receive enough calories from what it ate without depleting the species below it.
Given a set of microbes with different properties, select the combinations that perform best across multiple ocean sites. Each site has distinct conditions — you iterate on your choices and refine based on how combinations perform.
Candidate reports describe each site stating its requirements up front: target ranges for a few numeric attributes plus trait constraints (at least one team member must carry the desired trait; microbes with the undesired trait cost you). The trap most first-timers hit: the attribute ranges apply to your team's combined values, not to each microbe individually. CaseStar's free Sea Wolf simulator replicates this as a 30-minute run across 3 sites — 7 attributes rated 1-10 per microbe, 5 traits, a final team of 3 per site — with scoring that starts at 100% and deducts 20 points per violated constraint.
A research and data-interpretation task: work through written information, charts, and tables to answer a series of multi-step questions about a conservation-style scenario. More analytical and less visual than Sea Wolf.
Reported structure: a longer study case(Investigation → Analysis → Report — you collect relevant numbers into a journal, calculate with an on-screen calculator, then complete a written summary) followed by quick standalone mini-cases. CaseStar's free Red Rock simulator mirrors this: 35 minutes across a study case plus 6 mini-cases (~14 questions), with data tables and charts where roughly half the values are deliberate noise — because the skill Redrock rewards is triage, not just arithmetic. Its scoring weighs accuracy at 70% and process at 30%.
McKinsey is reportedly piloting a third Solve module, Sustainable Future Lab, starting in early 2026. It is a behavioral, scenario-based simulation focused on decision-making under uncertainty in a sustainability-framed team context — rather than the quantitative data work seen in Redrock or Sea Wolf.
Separately, McKinsey has reportedly begun piloting a Lilli-based AI case interview at select US final rounds. This is a distinct assessment from Solve, currently described as non-evaluative, and available at only a few offices. See the full guide for details.
The Solve assesses 5 cognitive abilities that predict consulting success:
| Ability | How It's Tested |
|---|---|
| Critical Thinking | Evaluating data, identifying constraints, spotting weak assumptions |
| Decision Making | Choosing microbe combinations (Sea Wolf) or picking interpretations (Redrock) |
| Meta Cognition | Adapting strategy when initial approach fails |
| Situational Awareness | Tracking how conditions differ between sites / datasets |
| Systems Thinking | Understanding interactions between variables in the scenario |
McKinsey provides a practice environment when you receive your assessment link. No third-party tool perfectly replicates the actual games, but general puzzle games and systems-thinking exercises help build relevant skills.
You can typically retake it after 2 years (one application cycle). Some offices may have different policies. Your case interview skills remain valuable for other consulting firms that don't use this assessment.
In most reported processes, no — Solve works as a screen, and candidates below the bar are not invited to interviews. McKinsey doesn't disclose how heavily it weighs Solve, though, and some candidate reports describe results being considered alongside resume strength rather than as a strict cutoff. Weighting appears to vary by office and recruiting cycle, so confirm specifics with your recruiter.
Different, not necessarily harder. The PST was a multiple-choice math and logic test. The Solve tests different cognitive abilities through interactive scenarios. Some candidates find the gamified format less stressful than timed math problems.
Yes. Your webcam records you during the assessment. You cannot pause, go back, or use external resources. Ensure stable internet and a quiet environment.
After passing the Solve, you'll face case interviews and PEI. Practice both with voice case simulations.
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