ZS Case Interview Practice: Free Case and Prep Resources
ZS's careers site publishes three practice cases, All-Star Airlines market entry, Zoltners pharma pricing and a consumer goods sunscreen launch, each with an answer revealed after every question. Unlike L.E.K.'s published cases, which give approach questions and no answers, ZS shows its answer to each step, so work each question out loud before you reveal it.ZS (opens in a new tab), read ; L.E.K. (opens in a new tab), read
Free, no signup: 3 worked cases with model answers. Free, no card: your first full practice case with an AI interviewer. Paid: Pro $49/month for every case.
Updated ·By Esteban Ronsin·Founder · former Deloitte and Accenture Strategy consultant
Built and reviewed with former McKinsey, BCG and Bain consultants and interviewers.
Free ZS interview prep resources
ZS interview prep resources: what you get, whether it is free or paid, and the link
Resource
What you get
Free or paid
Link
ZS case interview practice
ZS's own three practice cases (airline market entry, pharma pricing, consumer goods launch), each with an answer you reveal after every question
7 library cases matched to ZS's case types, run out loud with an AI interviewer or step by step and scored on 7 skills; start with MedSuite Technologies Hospital Software Pricing
Free + paid. The case overview is public; a free account includes 1 full AI-graded case in voice or guided mode; Pro ($49/month) adds every case
Halvering Valley Hospital: operations case with answers Industry: Healthcare. Difficulty: hard.2 math questions.
Why are four times as many patients walking out of a community hospital's emergency department before being seen, and which fix should the hospital fund? 7 questions, 4 exhibits, a model answer for each
Free. The whole case and every model answer, no account; the practice button opens a live case like it
Corbelworks: pricing case with answers Industry: B2B software. Difficulty: hard.1 math question.
Should a construction software company price its new scheduling app per seat, per project or in tiers, and at what price? 6 questions, 3 exhibits, a model answer for each
Free. The whole case and every model answer, no account; the practice button opens a live case like it
Dunmore Cargo Bikes: market sizing case with answers Industry: Mobility. Difficulty: easy.1 math question.
How big is the annual US market for electric cargo bikes sold to urban delivery couriers, and is it big enough for a $10 million revenue goal? 5 questions, 1 exhibit, a model answer for each
Free. The whole case and every model answer, no account; the practice button opens a live case like it
ZS fit and behavioral questions answered out loud, with follow-up probes and structured feedback (choose ZS on the page)
Free + paid. 1 behavioral or Learning Mode session with a free account; Behavioral Unlimited ($39/month, behavioral and PEI only) or any Pro plan adds more
Firm-style cases are practice cases written for Road to Offer or adapted from university consulting club casebooks, not the firm's own cases. Road to Offer is independent and not affiliated with ZS.
Try a free ZS-style case now: no card, no signup
An original practice case written by Road to Offer in a ZS-style format, not ZS's own case. Everything stays in your browser.
BW-12 Psoriasis Launch: Pricing and sizing a new psoriasis injection
A pharma launch, as in ZS's own Zoltners case: a pricing framework, a patient estimate, then a recommendation. The full version is MedSuite Technologies, our healthcare pricing case, which is not ZS's. ZS (opens in a new tab), read
1Step 1: Read the case
Brightwell Therapeutics expects approval in six months for BW-12, a once-monthly injection for moderate to severe plaque psoriasis. Two injectable competitors already treat patients. The CEO asks you to estimate how many US patients BW-12 can reach and to recommend a launch price.
2Step 2: Ask clarifying questions
Open a question to hear the interviewer's answer.
How does BW-12 compare with today's treatments?
Interviewer: It clears skin as well as the two leading injectables but is given once a month instead of every two weeks. There is no head-to-head safety data yet.
Who pays for it?
Interviewer: Insurers and government programs pay most of the cost; patients pay a small copay. Insurers decide whether the drug goes on their approved list, and often ask patients to try a cheaper drug first.
Which market, and over what period?
Interviewer: The US only, for the first three years after launch.
What does it cost to make?
Interviewer: About five thousand dollars per patient per year, so any price above that earns a margin.
What does leadership want?
Interviewer: A recommended price and the number of patients the drug can reach, so the CEO can judge the revenue. They want to win share quickly without giving up much margin.
3Step 3: Structure your answer
Take two minutes. Lay out how you would work out the patients BW-12 can reach and the price you would set.
2:00
Show what a strong structure covers
Plays back both asks, patients reached and a launch price, and the goal: share quickly without giving up much margin.
Builds a patient funnel: US population, people with psoriasis, moderate to severe disease, those on an injectable today, then the share BW-12 can win.
Looks at price through three lenses: the cost to make (the floor), the value to payers against today's treatments, and competitors' prices.
Raises payer access: approved-list placement, the gap between list and net price, and the step through a cheaper drug.
Forms a first hypothesis: priced close to competitors, with monthly dosing as the reason to prefer it, and says what it would test first.
Names the risks: no head-to-head safety data, payer pushback and competitors cutting their price.
4Step 4: The interviewer's next question
Assume the US has 330 million people, 2% have psoriasis, one in five of them has moderate to severe disease, and a third of that group is on an injectable today. How many patients is that?
Show what a strong answer does
About 6.6 million with psoriasis, about 1.3 million with moderate to severe disease, then about 440,000 on an injectable. A strong answer says each step out loud, rounds as it goes, then ties it to price: 10% of them is about 44,000 patients, and at thirty thousand dollars a year net that is roughly 1.3 billion dollars, which is why the net price payers accept matters.
Flour costs rose 18% on a $4M flour bill, and prices went up 3% on $20M of sales. How much margin did Harbor lose?
Your answer
Flour went up by about $720K and the price rise brings in $600K, so the net hit is roughly $100K.
What worked
Split the change into a cost side and a price side before adding them up.
Could improve
$720K minus $600K is $120K, not $100K: state the exact net before rounding.
Model answer
Flour: 18% of $4M is $720K more cost. Price: 3% of $20M is $600K more revenue. Net margin loss: $120K.
Next time, say this
Cost is up $720K and price brings back $600K, so Harbor loses $120K of margin.
3
1
Choose a case
Cases matched to ZS's case types.
2
Solve it out loud
An AI interviewer asks, listens and follows up.
3
Get answer feedback
Feedback on every answer: what worked, what to fix.
What makes ZS interviews different
Answers on the page.
Each question in ZS's practice cases has an answer behind a "Reveal answer" control, so you can check your own work step by step. Source: ZS, read (opens in a new tab)
Three industries.
ZS's practice cases cover an airline, a pharma company and a consumer goods company, so the case is not only pharma. Source: ZS, read (opens in a new tab)
Numbers inside the case.
Its pharma case asks for a patient count, doses per year, cost per dose and a capacity check, and its consumer goods case ends in a profit estimate for a customer segment. Source: ZS, read (opens in a new tab)
No perfect answer.
ZS says there is no perfect answer and that it looks at how you approach challenges, learn from feedback and bring new ideas. Source: ZS, read (opens in a new tab)
An expertise interview.
Besides behavioral and case interviews, ZS lists subject matter expertise interviews about your past projects, time management and stakeholder communication. Source: ZS, read (opens in a new tab)
An online assessment for some roles.
ZS says it covers logical, quantitative and qualitative reasoning plus big data concepts such as cloud platforms, data management, analytics and coding languages. Source: ZS, read (opens in a new tab)
Each arrow opens the source: ZS, read Nov 11, 2026.
Key facts from ZS's own pages
Three practice cases.
All-Star Airlines (new markets), Zoltners and SINHA (pricing a COPD drug) and Consumer Goods Co. (launching a sunscreen). Source: ZS, read (opens in a new tab)
Behavioral interviews, case interviews, subject matter expertise interviews and an online assessment, varying by role and location. Source: ZS, read (opens in a new tab)
Only certain roles have one, and ZS says the recruitment process may vary by role and location, so ask which steps yours includes. Source: ZS, read (opens in a new tab)
Each arrow opens the source: ZS, read Nov 11, 2026.
ZS's practice cases and interview pages, item by item
Everything ZS publishes on its careers site to prepare for its interviews, each opened on 11 November 2026. Each line is our summary of the item's own page. Read on ZS's site .
ZS's practice cases and interview pages, item by item: level, area and what each one is, linked to ZS's page
A profitable airline with plenty of cash and slow US growth explores new markets: how to decide, a first read of the research, a break-even and market-share calculation over three years, then a recommendation with risks and next steps. Answers revealed.
A pharma client expects approval of a COPD drug that cut severe episodes in trials and asks for a price: a pricing framework, patients, doses, cost per dose, competitors, a capacity decision, a recommended price, then risks. Three exhibits, answers revealed. Worked below.
A consumer goods company with a best-selling sunscreen plans a new formula: launch factors, marketing direction from product and market research, customer segments, a profit estimate for one segment and its channels. Answers revealed.
The page that lists the three practice cases: case interviews show the work and impact at ZS, there is no perfect answer, and ZS looks at how you approach challenges, learn from feedback and bring new ideas.
The four kinds of step (behavioral, case, subject matter expertise and an online assessment for certain roles) and an FAQ on assessments, rounds, video interview timing and local language.
Programs by region, including case workshops in Europe that teach structured problem-solving and interview prep, and case challenges in India led by alumni ambassadors.
Worked: Practice case two: Zoltners and SINHA, in ZS's three pricing lenses: cost-based, value-based and competition-based
Zoltners expects approval of SINHA, a COPD drug that cut severe episodes by a best-in-class 30% in trials, and asks ZS to help set its price. The goal is to gain share fast without giving up strong profit. Read the official case (opens in a new tab)(read )
How you might work it is ours, not ZS's answer key.
1
Frame the price with three lenses
Say that price rests on cost (the floor), on value (what patients and payers will pay, given the trial result and the pipeline) and on competition (rival prices, shares and performance). Name which lens you expect to decide it, and promise to come back to the frame at the end.
2
Size the patients
Take the stated share of the US population, round the population to a figure you can multiply, and note that the client called the share an estimate, so confirm with the interviewer whether a rounded figure is fine before you move on.
3
Read willingness to pay, then doses
If patients already complain about current prices, say that caps any premium. Then turn every-other-week dosing into doses per patient per year, and sanity-check it against the fifty-two weeks in a year.
4
Get cost per dose from the exhibit
Divide each production cost, materials, labor and distribution, by the doses that cost covers, then add the three. That is the floor under every price you test.
5
Hypothesize the competition, then reconnect
From the two rivals' prices and shares, say how patients split between the more effective drug and the cheaper one, and what that means for SINHA. Then run the finding through each lens in turn, so the framework and the numbers say the same thing.
6
Test the capacity decision
Annual doses are working hours times doses per hour. Divide by doses per patient to get patients treatable per year, then compare with the market to see how much of the production capacity is in use, and say what that means for doubling it.
7
Recommend a price and name the risks
Give one price with its reason, tied to the goal of fast share without losing profit. Then raise risks (safety against efficacy, and the sales and marketing spend to hold share) and the next steps that would validate it. ZS reveals its own answer on the page: try yours first.
ZS says it is looking for how you “approach challenges, learn from feedback and bring new ideas to the table”, and that “there is no perfect answer”. Source: ZS, read (opens in a new tab)
A real business challenge
ZS describes the case interview as tackling “a real business challenge”: structure the problem, develop solutions, apply feedback and think creatively. Source: ZS, read (opens in a new tab)
Quality of work on past projects
For the subject matter expertise interview, ZS says questions focus on your past projects, relevant responsibilities and how you ensure high-quality results. Source: ZS, read (opens in a new tab)
Problem-solving and leadership (graduates)
For graduates ZS says it focuses on “performance, leadership and problem-solving skills”, and that critical thinkers with curiosity, creativity and an entrepreneurial drive will find challenges. Source: ZS, read (opens in a new tab)
A two-way conversation
ZS calls its interview process “a two-way conversation” to explore your experiences and goals, and says you will meet ZSers who can tell you about the role, the culture and the firm. Source: ZS, read (opens in a new tab)
Each arrow opens the source: ZS, read Nov 11, 2026.
The ZS interview process, and what trains each step
1
Behavioral interviews
ZS says behavioral interviews help it get to know you and assess your fit for the role; they vary by position and may include conversations with your recruiter and other ZSers. ZS lists its steps without an order, and says the process may vary by role and location.
ZS says you will tackle a real business challenge, showing how you structure problems, develop solutions, apply feedback and think creatively, and links its case interview preparation page.
ZS assesses your subject matter expertise, quality of work, time management, stakeholder communication and problem-solving, with questions about your past projects, relevant responsibilities and how you ensure high-quality results.
ZS says certain roles require an online assessment covering logical, quantitative and qualitative reasoning, along with big data concepts such as cloud platforms, data management, analytics and coding languages. Your recruiter walks you through the process for your role.
ZS says candidates can typically expect two to four rounds, depending on role, level and region. Its FAQ mentions a video interview, with an answer expected two to four weeks later during the busy campus hiring season.
Missing from ZS's pages: how long each interview lasts, who leads the case, how answers are scored, which roles get the online assessment and who provides it, whether any round uses a written case, which round each step falls in, and when offers are made.
14 ZS-style interview questions
In our words, not ZS's, grouped by the steps ZS names and by its three practice cases, with what a strong answer does.
Case interview: entering a new market (practice case one)
ZS's airline case asks for a framework, a first read of the research, a break-even calculation and a recommendation with risks.
1A profitable regional grocery chain with plenty of cash expects slow growth at home and is weighing a new region. How do you decide whether to enter?
What a strong answer does: Frames it as the profit the new region could earn, with hypotheses and the questions behind them: what customers pay, how soon the chain must break even and what regulation or competitors stand in the way.
2A table shows region B with the highest sales but two to three times the entry cost, and region C growing fastest with few competitors. Without calculating, what is your first reaction?
What a strong answer does: Says what each region has going for it, names the trade-off between size and cost of entry, and states that a break-even timeline is what will separate them.
3The client wants to break even within three years of entry. How do you find the market share it needs in each region?
What a strong answer does: Divides fixed costs by the margin per unit to get the units needed over three years, then divides by the market size for the share, and says whether that share is realistic.
Case interview: pricing a drug (practice case two)
ZS's pharma case builds a pricing framework, then goes through patients, doses, cost per dose, competitors and capacity.
4A new drug cut severe episodes by 30% in trials and is about to be approved. What should the maker consider when setting its price?
What a strong answer does: Lays out cost, value and competition as the lenses, adds what patients and payers will pay, and names which one it expects to matter most.
5About 5% of US adults have a chronic lung disease. How many patients is that, and how exact does the number need to be?
What a strong answer does: Multiplies a rounded population by the share, treats the result as an estimate, and checks with the interviewer whether rounding it further is fine.
7Two rivals already treat patients: one more effective, one cheaper. What do you hypothesize about how patients split and where a new drug's price fits?
What a strong answer does: Expects the more effective drug to hold more patients, the cheaper one to keep the cost-sensitive ones, and a new drug to price near the cheaper rival if its edge is clinical.
8The maker can double production. How do you decide whether it is worth it?
What a strong answer does: Works out patients treatable per year from output and doses per patient, compares it with the market and with the share it can win, and says what would change the answer.
Case interview: launching a product (practice case three)
ZS's consumer goods case covers launch factors, marketing direction, segments, a profit estimate and channels.
9A company that sells a beach sunscreen is launching a premium daily-use one at several times the price. How do you check whether it will eat the first product's sales?
What a strong answer does: Compares the two on who buys, when and why, concludes that different uses mean low overlap, and says what premium pricing means for channels and branding.
10You get a table of customer segments by size, growth and how often they use the product. Which segment do you launch to first?
What a strong answer does: Ranks segments on size, growth and fit with the product, picks one to launch to and one to widen to later, and says what research would confirm it.
11Estimate yearly profit for one segment of a new product, given the price and the cost to make it.
What a strong answer does: Runs population, share in the segment, regular users, market share and purchases a year, multiplies by profit per unit, and says which assumption is shakiest.
13How did you manage your time and keep stakeholders informed on your last big project?
What a strong answer does: Names the stakeholders and what each needed, the rhythm of updates, and one moment it changed the plan because of what it heard.
ZS names logical, quantitative and qualitative reasoning; practise the quantitative part under time.
14A drug's share of treated patients fell from 40% to 30% while the number of treated patients grew from 2.0 to 3.0 million. Did its patient count fall?
What a strong answer does: Multiplies share by patients for both years, about 0.8 million and then 0.9 million, so the count rose, instead of reading the share alone.
ZS says there is no perfect answer. Show your structure, say your assumptions and change your answer when the data does. Source: ZS, read (opens in a new tab)
Revealing the answer too early
ZS hides each answer behind a "Reveal answer" control. Answer out loud and timed first, or you only practise reading. Source: ZS, read (opens in a new tab)
Preparing for pharma only
ZS's three practice cases cover an airline, a pharma company and a consumer goods company. Train structure, sizing and math first, then the pharma vocabulary your role needs. Source: ZS, read (opens in a new tab)
Not checking an estimate
In ZS's pharma case the client calls the patient share an estimate. Confirm with the interviewer that a rounded figure is fine before you build on it. Source: ZS, read (opens in a new tab)
Ending without risks and next steps
ZS's airline and pharma cases both end by asking for risks and next steps. Give one recommendation, then what could make it wrong and how you would check. Source: ZS, read (opens in a new tab)
Each arrow opens the source: ZS, read Nov 11, 2026.
A ZS prep plan, day by day
The order follows ZS's own pages; the timing is our suggestion.
Days 1 and 2
Read ZS's own pages
Read the interview process and the case interview preparation pages, then check what your invitation says about the online assessment and the rounds.
How should I prepare for the ZS Associates case interview, and which free resources should I use?
Start with ZS's own case interview practice page: work its three practice cases (All-Star Airlines market entry, Zoltners drug pricing and a consumer goods sunscreen launch) out loud before you reveal each answer, then train what they test: a framework, market sizing, math from an exhibit and a recommendation with risks. If your role has an online assessment, add timed math and chart reading. On Road to Offer a free account includes 1 full AI-graded case, such as MedSuite Technologies, a healthcare pricing case; Halvering Valley Hospital, Corbelworks (pricing) and Dunmore Cargo Bikes (market sizing) are worked cases with a model answer for every question and need no account. Firm-style cases are practice cases written for Road to Offer or adapted from university consulting club casebooks, not the firm's own cases.
Where can I practice ZS Associates-style case interviews for free?
On this page: the ZS-style pharma launch case runs in your browser with no account, with the interviewer's answers to your clarifying questions, a timer and a notes box. ZS's careers site has its own three practice cases, free, with answers you reveal after each question. On Road to Offer, MedSuite Technologies runs out loud with an AI interviewer; your first full case is free with a free account, no card. Halvering Valley Hospital, Corbelworks and Dunmore Cargo Bikes are free to read with a model answer for every question, no account.
What practice cases does ZS Associates publish, and how should I use them?
Three, on ZS's case interview practice page. Practice case one is All-Star Airlines, a profitable airline with slow US growth weighing new markets: a framework, a first read of the research, a break-even and market-share calculation, then a recommendation with risks. Practice case two is Zoltners and SINHA, a COPD drug awaiting approval: build a pricing framework, size the patients, work out doses and cost per dose from an exhibit, hypothesize the competition, test a capacity decision, then recommend a price. Practice case three is a consumer goods company launching a new sunscreen: launch factors, marketing direction, customer segments, a profit estimate and channels. Each question has a hidden answer behind "Reveal answer". Answer out loud and timed first, then compare, and redo the step you missed.
Is the ZS case interview only about pharma and life sciences?
No. ZS's three published practice cases cover an airline, a pharma company and a consumer goods company, and ZS says only that the process varies by role and location. Prepare the structure, sizing and math that every case needs, and add the pharma basics (patients, payers, price per dose) if your role is in life sciences. Road to Offer has no case written by ZS; the library cases are general practice cases chosen for this page.
Does ZS have an online assessment?
For certain roles. ZS's interview process page says certain roles require an online assessment covering logical, quantitative and qualitative reasoning, plus big data concepts such as cloud platforms, data management, analytics and coding languages, and that your recruiter will walk you through the process for your role. ZS does not publish its length, scoring or provider. Road to Offer has no ZS test simulator; the closest practice is timed case math and chart drills.
How many interview rounds does ZS have?
ZS says candidates can typically expect two to four rounds, and that the process differs by role, level, region and other factors. Its page names four kinds of step: behavioral interviews, case interviews, subject matter expertise interviews and an online assessment for certain roles. ZS does not say which come in which round, so ask your recruiter for the sequence for your role.
Is the ZS case interview candidate-led or interviewer-led?
ZS's pages don't say. Its practice cases are written as a numbered sequence of questions, each building on the last, which reads like an interviewer who steers; candidate reports differ. Practise both: opening with your own framework, and answering one directed question at a time with a number.
Does ZS ask market sizing questions?
Its own practice cases do. Practice case two asks you to turn a share of the US population into a patient count, then doses per patient per year, and practice case three builds a profit estimate for one customer segment from a population, a usage rate and a market share. Practise a clear funnel, with each assumption said out loud and rounded sensibly.
What is the ZS subject matter expertise interview?
ZS says it assesses your subject matter expertise, quality of work, time management, stakeholder communication and problem-solving, with questions about your past projects, your responsibilities and how you ensure high-quality results. Prepare two or three projects with what you owned, how you managed time and people, and the result with a number; Road to Offer's ZS fit practice asks questions with follow-up probes, 1 session free with a free account.
How long does ZS take to reply after a video interview?
ZS's FAQ says to expect anywhere from two to four weeks during the busy campus hiring season, and that it is working to answer all candidates in a timely manner. It does not give a figure outside campus season, so ask your recruiter.
Do I need to speak the local language to interview at ZS?
ZS says all ZSers must speak English, with a second language preferred in certain offices, and that ZSers in Germany and Japan are required to speak the local language in addition to English. Check the posting for your office.
How long is a ZS case interview, and how is it scored?
ZS publishes neither. Its practice page says there is no perfect answer and that it is looking for how you approach challenges, learn from feedback and bring new ideas. Treat that as the scoring hint: show your structure, say your assumptions, take the interviewer's feedback and change your answer when the data changes.
