Cushman & Wakefield · Data Scientist
Updated · 2026-09-24

Cushman & Wakefield Data Scientist
Interview Questions & Guide 2026

THE 60-SECOND BRIEF

As a Data Scientist at Cushman & Wakefield, you are at the intersection of global real estate strategy and cutting-edge analytical modeling. You will work within one of the world’s largest commercial real estate services firms, where your ability to synthesize vast datasets into actionable insights directly influences multi-million dollar investment decisions, portfolio optimizations, and workplace strategy.

Nearly every loop contains a round whose deliverable is a recommendation to someone non-technical. Practise stating a conclusion, the confidence attached to it, and the cost of being wrong in each direction, because that triple is the artifact being graded.

PracHub has no confirmed round sequence for Cushman & Wakefield. Treat the sections below as preparation areas and confirm the format with your recruiter.

Define numerator, denominator and window preciselyDecompose a metric move by segment and mixSeparate novelty effects from durable behaviour change

28 min read

Browse Data Scientist questions

See the practice prompts

13Practice promptsAcross five skill areas
3With worked solutionsIncluded in the practice prompts

As a Data Scientist at Cushman & Wakefield, you are at the intersection of global real estate strategy and cutting-edge analytical modeling. You will work within one of the world’s largest commercial real estate services firms, where your ability to synthesize vast datasets into actionable insights directly influences multi-million dollar investment decisions, portfolio optimizations, and workplace strategy.

The role is critical because Cushman & Wakefield manages complex, high-stakes environments—from corporate office footprints to industrial logistics centers. You will be expected to build predictive models, automate reporting pipelines, and leverage machine learning to help clients navigate market volatility and operational efficiency. It is a position of significant influence, requiring you to bridge the gap between technical rigor and business-focused storytelling.

Total packages for this role within the Cushman & Wakefield organization may vary based on location and specific team requirements. During negotiation discussions, focus on the value your analytical skills bring to the firm’s bottom line.

01

Preparation focus

editorial

No round sequence has been reported for this company, so work the categories below and confirm the format with your recruiter.

What to demonstrate

  • Breadth across SQL, experimentation and product reasoning
  • Ability to state assumptions before choosing a method

How to prepare

  • Drill the practice exercises below and time yourself
  • Prepare three quantified stories about decisions you drove
PracHub interview preparation framework ↗

PracHub editorial advice for the preparation topics above.

01

Watching an experiment daily and stopping when it crosses significance

A fixed-sample test controls type I error at one pre-declared look. Checking repeatedly and stopping at the first p < 0.05 inflates the false positive rate to roughly 0.15 to 0.20 for ten looks, and it rises further with more frequent checks, because the p-value takes a random walk that will eventually dip below the threshold under the null. The usual defences are a fixed horizon declared before launch, group-sequential boundaries such as O'Brien-Fleming that spend alpha across a planned number of looks, or always-valid confidence sequences that are correct under continuous monitoring. Compounding it, the effect size reported conditional on having crossed the threshold is biased away from zero, and the bias is larger the lower the power was, so an underpowered test that 'won' typically overstates the lift it found.

02

Counting on an identity key that changes underneath the metric

visitor_id is per browser and per device, and it resets on cookie clearance, private browsing and platform privacy changes, so the distinct-visitor count drifts upward for reasons unrelated to reach. Any rate with visitors in the denominator therefore decays over time even when behaviour is constant, and any rate with visitors in the numerator inflates. The stitching at signup makes it worse in both directions: a user who signed up on mobile and returns on desktop is two visitors and one user, while a shared device is one visitor and several users. Decide which key each metric is counted on, write it into the definition, and when comparing a period before and after a platform privacy change, expect a level shift in every visitor-keyed metric and do not attribute it to the product.

03

Naming a model class before naming the deployment constraints

Set out the latency budget, the label delay, the retraining cadence, the interpretability requirement and the number of labelled examples, then pick the model that fits them. A boosted-tree answer to a problem where each decision must be explained to the affected user is a well-executed answer to the wrong question.

04

Extrapolating a first-week lift inflated by novelty effects

Plot the treatment effect by days since first exposure instead of quoting one pooled average. A lift that decays toward zero across the test window is behaviour that will not persist, and annualising it produces a forecast that misses by an order of magnitude.

Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.

10 technical prompts3 include a worked solution

Explain the difference between bagging and boosting, and provide an ex…

medium
statistics and probability

Explain the difference between bagging and boosting, and provide an example of when you would use each.

Approach
  1. Write down the assumption the method needs before you use the method.
  2. Say what the estimate is of, and over what population it generalises.
  3. Sanity-check the answer against a simple bound or a simulated case.
Follow-up
  • What sample size would you need to detect an effect half this size?
  • Which assumption here is most likely to be violated in practice?

How would you design a model to predict vacancy rates for a portfolio …

medium
machine learning and modelling

How would you design a model to predict vacancy rates for a portfolio of commercial properties?

Approach
  1. Pick an evaluation metric that matches the cost of each error type, not a default.
  2. Frame the prediction: the label, the moment of prediction, and the action it triggers.
  3. Check what information would not exist at prediction time, and exclude it.
Follow-up
  • How would you choose the decision threshold, and who owns that choice?
  • What would you monitor after launch to know the model is still valid?

How do you prioritize which features to include in a model when faced …

medium
machine learning and modelling

How do you prioritize which features to include in a model when faced with a high-dimensional dataset?

Approach
  1. Say how the offline result would be validated online before it is trusted.
  2. Set a baseline first, so any model has something honest to beat.
  3. Check what information would not exist at prediction time, and exclude it.
Follow-up
  • Where could label leakage enter this setup?
  • How would you choose the decision threshold, and who owns that choice?

What are the assumptions of linear regression, and how do you validate…

medium
machine learning and modelling

What are the assumptions of linear regression, and how do you validate them?

Approach
  1. Say how the offline result would be validated online before it is trusted.
  2. Check what information would not exist at prediction time, and exclude it.
  3. Set a baseline first, so any model has something honest to beat.
Follow-up
  • Where could label leakage enter this setup?
  • How would you choose the decision threshold, and who owns that choice?

Simulate the false positive cost of repeated peeking

mediumWorked solution
simulationpeekingtype i error

Quantify the cost of peeking. Simulate a two-arm experiment with no true effect: each arm accumulates Bernoulli conversions at a base rate of 0.10 up to 40,000 units per arm. Run a two-sided two-proportion z-test at alpha 0.05 at ten equally spaced interim points, and record whether the test ever crossed. Report the false positive rate over at least 10,000 replications, alongside the rate for a single look at the final sample only. Use a fixed seed and report a Monte Carlo standard error on both figures.

Approach
  1. Generate each replication as two cumulative sums of Bernoulli draws, then read the interim points off the cumulative arrays. Regenerating data at each look would make the looks independent, which destroys exactly the dependence the exercise is about: later looks share data with earlier ones.
  2. Use the pooled-variance two-proportion z: p_pool = (x1+x2)/(n1+n2), z = (p1-p2) / sqrt(p_pool*(1-p_pool)*(1/n1 + 1/n2)), reject when |z| > 1.96. State that the normal approximation is fine here because the smallest look has roughly 400 expected conversions per arm.
  3. Vectorise across replications rather than looping: draw a (reps, n) array of uniforms, threshold at 0.10, cumsum along axis 1 and slice the ten look indices. A per-replication loop at 10,000 by 40,000 is unnecessarily slow.
  4. Record the any-cross indicator per replication, take the mean, and compute the Monte Carlo standard error as sqrt(p*(1-p)/reps) so the reported figure comes with its own precision.
  5. Report the single-look rate in the same run as a control. If it does not land near 0.05, the bug is in the test statistic and not in the peeking argument.
Worked solution 30 min
  1. rng = np.random.default_rng(seed); for memory, batch the replications in chunks and accumulate the any-cross count across chunks.
  2. Per chunk: draw (chunk, 40000) uniforms per arm, x = (u < 0.10).cumsum(axis=1), slice columns at indices 3999, 7999, ..., 39999.
  3. Compute the ten z statistics vectorised over the chunk, take crossed = (np.abs(z) > 1.96).any(axis=1).
  4. Aggregate: peek_rate = total_crossed / reps; single_rate = mean of |z_final| > 1.96; mc_se = sqrt(p*(1-p)/reps) for each.
EXPECTED RESULTThe single-look rate lands at 0.05 within about 0.005 at 10,000 replications. The ten-look rate lands near 0.19, which with 10,000 replications has a Monte Carlo standard error of about 0.004, so anything in roughly 0.18 to 0.20 is consistent and anything near 0.40 indicates independent redraws.
Follow-up
  • Re-run with 40 looks instead of 10. Why does the curve flatten rather than continue rising linearly?
  • Among the replications that crossed, what is the mean observed lift, and why is it not zero?
  • What does an O'Brien-Fleming boundary or an always-valid confidence sequence change about this simulation, and what does each cost in power?

Four days spend equal time on query work, statistics, modelling and product judgement at deliberately shallow depth, which produces a scored map of where you actually stand. The last three days spend everything on the two areas the role weights most, and close by re-running day one to measure movement.

Small steps. Visible outcomes.0 / 7 completed
ONE WEEK · YOUR PACE

Prepare, practise & reflect

One practical outcome each day. Spend longer where you need it.

0 / 7 done
01Breadth pass: query fluency
  • Solve six prompts spanning aggregation, joins, window functions and date arithmetic in 60 minutes total, stopping at 10 minutes each whether or not it works, and mark every prompt as solved, solved slowly, or stuck.
  • For each unsolved prompt write the single blocking sentence (I lost the grain, I did not know the frame clause, I could not express the date boundary) instead of reading the solution.
  • Translate one pandas transformation you know well into SQL and one SQL query into pandas, checking that both return the same row count and the same totals.

Deliverable: A scored six-row table, one line per prompt, saved for the day-seven re-run.

Practice prompt ↗Practice prompt ↗Worked solution ↗
02Breadth pass: statistics and inference
  • Answer ten short questions in writing with nothing open: what a p-value is conditional on, what a 95 percent interval covers across repeated samples, when a paired test is the right one, what the bootstrap estimates, why multiple comparisons inflate false positives, how controlling the family-wise error rate differs from controlling the false discovery rate, what power depends on, what a missed real effect costs a product, the three situations where the central limit theorem does not rescue you (small n, very heavy tails, dependent observations), and what a standard error is the standard deviation of.
  • Grade yourself against a reference and count only the answers that were exactly right, not the ones that were nearly right.
  • Rewrite the two weakest answers the following morning from memory in full sentences.

Deliverable: Ten graded answers with an honest count of exact hits.

Practice prompt ↗Practice prompt ↗
03Breadth pass: modelling
  • Take one tabular dataset end to end in 90 minutes: a leakage-safe split, a baseline that is not a model (majority class or historical mean), one regularized linear model, one gradient-boosted tree, and a single evaluation metric chosen before you look at any result.
  • Write why that metric fits the cost structure: precision at a fixed recall for alerting, calibration for anything feeding a price or a threshold, ranking metrics for retrieval, and note that area under the ROC curve is insensitive to class balance in a way that can flatter a rare-positive problem.
  • Name the leak you were most likely to introduce (an encoding fit on all rows before splitting, or a feature computed after the label's timestamp) and write the check that would have caught it.

Deliverable: A notebook whose first cell states the metric and the baseline, plus two lines on what beat what and by how much.

Practice prompt ↗Practice prompt ↗
04Breadth pass: product judgement
  • Answer three case prompts aloud at 15 minutes each, timing how long passes before you state a success metric.
  • For one case write the first segmentation you would run and the row counts you expect per segment, so that a tiny segment cannot quietly drive the conclusion.
  • Take a metric definition you did not write, from a public dashboard, a textbook, or documentation you already have open, and list every place two analysts implementing it would diverge: which rows the denominator admits, whether the unit is an account or a person, what the time window is anchored to, and what happens to data that arrives late. Then write the one question that would close the largest of those gaps.

Deliverable: Three recorded case answers plus an ambiguity list for a metric someone else defined, ending in the single question you would ask about it.

Practice prompt ↗Practice prompt ↗Worked solution ↗
05Depth, first area
  • Rank the four areas by how many bullet points in the role description each one covers, pick the top one, and spend the entire day inside it.
  • Work the six hardest problems you can find in that area and for each write the generalizable move you should have reached for first, rather than the answer.
  • Re-solve the two you failed the same evening with notes closed.

Deliverable: Six generalizable moves written as instructions to yourself, not as solutions.

Practice prompt ↗Practice prompt ↗
06Depth, second area, and the seam between them
  • Repeat the depth protocol on the second-ranked area with the same six-problem structure.
  • Construct one problem that requires both areas at once, for example a metric redefinition whose effect you must validate with a test whose readout you then have to query.
  • Solve your own combined problem end to end and note where the handoff between the two areas cost you time.

Deliverable: One combined problem, solved end to end, with the handoff failure written down.

Practice prompt ↗Practice prompt ↗
07Integration and re-measurement
  • Re-run the six prompts from day one under the same clock and compare both correctness and time.
  • Run a 60-minute mixed mock that moves between areas without warning, since switching cost is what breadth passes do not train.
  • Write the two areas you would still fail on, and the sentence you will use in the interview when you hit one of them.

Deliverable: A before-and-after score table plus a written plan for the two remaining gaps.

Practice prompt ↗Worked solution ↗

Expand any day for tasks and deliverables. Your progress is saved on this device.

Saying no well is a senior skill and it is rarely rehearsed. Think of a time you told someone their analysis was not worth doing, or that the experiment could not answer their question at the sample size available. Explain what you offered instead. Refusal without an alternative reads as obstruction rather than judgement.

Can you describe a time you had to explain a complex statistical model…

medium
behavioural and stakeholder questions

Can you describe a time you had to explain a complex statistical model to a non-technical stakeholder?

Approach
  1. Quantify the outcome, including what you would not claim credit for.
  2. Pick a story where you drove the decision, not one where you observed it.
  3. Close with what you would do differently, concretely.
Follow-up
  • How did you know the outcome was caused by your change?
  • What would you do differently if you ran that project again?

How do you handle missing or corrupted data in a large dataset?

medium
behavioural and stakeholder questions

How do you handle missing or corrupted data in a large dataset?

Approach
  1. Name the disagreement or constraint, and how you resolved it with evidence.
  2. Close with what you would do differently, concretely.
  3. Pick a story where you drove the decision, not one where you observed it.
Follow-up
  • What did you decide not to do, and why?
  • How did you know the outcome was caused by your change?

Disagree with a product manager's roadmap claim using data

medium
causal inferenceselection biasstakeholder

A product manager proposes building a feature on the argument that accounts connecting an integration in week one retain three times better at week four. The figure is correctly computed from dim_user and fct_event, and it has already been shown to leadership. You have one scheduled 1:1 before the roadmap locks. Deliver the specific analysis you would run to test whether the relationship is causal, the result that would change your own mind, and how you open the conversation so that the PM is not put in the position of defending the number in public.

Approach
  1. Recognise what is being probed: whether you can separate a number being right from an inference being wrong, and do it without costing the PM face. The generic answer recites that correlation is not causation; the strong one names the specific confound and proposes the cheapest design that could distinguish the explanations.
  2. State the alternative concretely. Accounts that connect an integration in week one are accounts that already have a workflow and a technical owner, so week-one intent plausibly drives both the connection and week-four retention. The selection is on intent, which no amount of post-hoc adjustment observes.
  3. Order the discriminating analyses by cost. First, condition on pre-connection activity by comparing retention within strata of week-one core-action count, which removes the crude version of the confound but not unobserved intent. Second, look for variation in integration availability that was unrelated to intent, such as a staggered release or an outage window. Third, an encouragement design that randomises a prompt to connect and reads the intent-to-treat effect on week-four retention, which is the only version that identifies an effect.
  4. Run the timing check, because it is nearly free and it is the most persuasive single piece of evidence. If the retention advantage among connectors is already visible before any of them connected, the causal story is largely finished.
  5. Pre-commit to what would change your mind and say it before you show anything: if the gap survives stratification and the encouragement arm moves week-four retention at all, the feature has a case and you will say so.
  6. Open the 1:1 by agreeing with the true part, that the correlation is real and worth chasing, then ask what effect size the roadmap plan assumes. That makes the size of the claim the topic instead of its authorship.
Follow-up
  • The encouragement test needs six weeks and the roadmap locks in two. What do you recommend in the interim?
  • Stratifying on week-one activity closes half the gap. What do you conclude, and what do you still not know?
  • How would you word this in the roadmap document so the PM's original number is reframed rather than deleted?
  • 01

    Can you describe a time you had to explain a complex statistical model to a non-technical stakeholder?

  • 02

    How do you handle missing or corrupted data in a large dataset?

  • 03

    A product manager proposes building a feature on the argument that accounts connecting an integration in week one retain three times better at week four. The figure is correctly computed from dim_user and fct_event, and it has already been shown to leadership. You have one scheduled 1:1 before the roadmap locks. Deliver the specific analysis you would run to test whether the relationship is causal, the result that would change your own mind, and how you open the conversation so that the PM is not put in the position of defending the number in public.

PracHub interview preparation framework ↗
Is this an official Cushman & Wakefield interview guide?

No. It is PracHub's own research and practice material for the Data Scientist role at Cushman & Wakefield. Rounds and questions reflect what candidates have reported, not a process Cushman & Wakefield has published, and they change over time. Confirm the current format and scope with your recruiter.

PracHub interview research ↗
How long does the interview process typically take?

Most candidates complete the process within 3 to 6 weeks. This timeline allows for thorough technical evaluation and multiple rounds of stakeholder interviews.

PracHub interview research ↗
Is the technical assessment done live or as a take-home?

Expect a combination of both. You may be asked to perform live coding during a screen, followed by a deeper case study or data challenge that you will present to the team.

PracHub interview research ↗
What is the culture like for the data team?

The culture is highly collaborative and results-oriented. You will be expected to be proactive in your communication and to advocate for your findings with data-backed evidence.

PracHub interview research ↗
Are there opportunities for remote work?

Specific arrangements vary by location and team. Be prepared to discuss your preferences during the initial recruiter screen, keeping in mind that Cushman & Wakefield values in-person collaboration for high-stakes projects.

PracHub interview research ↗
Sources & methodology 3 sources ↗

No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.