EY-Parthenon is EY's strategy arm. The case is usually an investment decision. A transformation roadmap is the wrong close.
EY bought The Parthenon Group in 2014 and kept a separate brand around transformative strategy and transactions. Commercial due diligence, valuation, and corporate strategy sit in the same service line. EY defines commercial due diligence as analysis of a target's market, customers, and competitive position plus growth potential and risks; that definition is close to a case structure. Published prep guides describe first rounds of roughly 30–60 minutes with fit attached, two to three rounds over about 6–12 weeks (CoachNed's behavioral note also cites four to eight weeks; treat both as directional). Interviewers filter backup applicants even with a clean case. Glassdoor reviews compiled on the EY-Parthenon behavioral page put fit at 40–50 percent of the evaluation. Headcount figures disagree: one guide says over 9,000 strategy professionals in 40+ countries; another about 10,000 across 45+ offices in 25 countries with a London global head office. Do not quote a precise headcount to a partner. Pay sits above general EY Consulting; see EY consulting salary. CoachNed is independent and not affiliated with EY.
What EY-Parthenon actually runs
EY early-career guidance still applies at the network level: an online skills assessment invitation within one business day, application incomplete until it is done. PrepLounge-style notes describe a timed numerical reasoning assessment, then fit-and-case rounds, then a senior final. Structured written cases are reported with 15–20 pages of material. Group cases of 60–75 minutes appear in many European assessment centres and some US finals. Format reports mix candidate-led and interviewer-led; do not assume BCG purity. Confirm the invitation.
| Stage | Format | What it scores |
|---|---|---|
| Recruiter screen | ~30 min, almost all behavioral | Why EYP, not MBB backup |
| Online numerical | Timed reasoning (EY network assessment) | Speed and accuracy |
| First round | Two ~30 min interviews; one often full fit plus a case | Diligence structure, conviction |
| Final | Two or three 30–45 min slots with SM/partners | Buy/no-buy quality, partner-ready fit |
| Written / group | Packet; 60–75 min team variant in some centres | Prioritisation and teamwork |
Worked diligence examples live in EY-Parthenon practice cases.
How EYP differs from McKinsey interviewer-led and BCG candidate-led
McKinsey leads you through exhibits. BCG lets you drive a generalist strategy case and close on a recommendation. EY-Parthenon wants a position on a deal: buy, no-buy, or buy at another price. A BCG-quality diagnosis that lists risks and stops is an incomplete EYP case. McKinsey's interviewer-led path can hide a weak ability to choose the analysis; EYP (when candidate-led) makes you pick market versus target versus price as the first test. When an interviewer does steer, it is often toward the multiple: "They want 11×. What are they asking for?"
EY Consulting cases, by contrast, end on a programme business case. Practising only those will under-train return math. Practising only McKinsey PEI will under-train the backup test: would you still want EYP if McKinsey called tomorrow?
Worked snippet: commercial due diligence (PE / life-sciences-adjacent flavour)
Prompt. A fund is looking at a specialty-pharma asset: $32 million EBITDA, asking 11× ($352 million). The indication is growing 7% a year. The fund needs a 2.5× cash-on-cash in five years with exit at 10×. Organic EBITDA would have to grow how fast, and do you buy?
Clarify. No leverage detail in the prompt; state you are looking at enterprise value in / enterprise value out, and ask whether bolt-ons are allowed in the thesis.
Structure. EY's own diligence description maps to four tests: market attractiveness, target position, economics of the price, what would flip you.
Math. Exit EV = $352 million × 2.5 = $880 million. At a 10× exit, required year-5 EBITDA = $88 million. From $32 million to $88 million in five years is 88/32 = 2.75×, or about 22% compound growth. Market growth of 7% plus modest share gain does not get you to 22%. A roll-up that adds $20 million of EBITDA at a cheaper multiple could close part of the gap; without it, the 11× ask implies a growth story the market does not support.
Recommendation. No-buy at 11×. Buy interest at ~9× ($288 million) only with a named roll-up pipeline. Risk: patent cliff not in the 7% market figure. Next step: loss-of-exclusivity dates and top-ten customer concentration before IC.
That is EYP-shaped: a hurdle, a required growth rate, and a price, not a market-study.
How to prepare this week
- If the role is EY Consulting, leave this page.
- Drill multiples, EBITDA bridges, and "what growth is implied." Use the practice-cases page.
- Run a live acquisition case on CoachNed.
- Write three Why EYP reasons you could not reuse at BCG. Rehearse with the behavioral guide.
- Check Parthenon versus Consulting pay on the EY consulting salary page.
Sources
- EY definition of commercial due diligence; 2014 Parthenon acquisition
- EY early-career application guidance
- PrepLounge EY-Parthenon process notes (four-stage funnel, written-case length)
- CoachNed EYP practice-cases and behavioral pages (round timings; 9,000 vs 10,000 headcount disagreement; Glassdoor fit weight)
Frequently asked questions
Is this the EY Consulting interview?
No. Different ending (investment decision) and a harder conviction test.
Candidate-led or interviewer-led?
Both are reported. Drive until you are steered.
Do sources agree on size?
No. Quote a range or skip the number. CoachNed is independent practice, not affiliated with EY or EY-Parthenon. Cases on CoachNed are AI-simulated. Office and country change written and group use.