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Arag Legal Insurance Data Scientist Interview Questions & Guide 2026

Causal inference drills for Arag Legal Insurance data scientist prep: diff-in-diff, matching, instruments, and the limits of observed data.

The 60-second brief

As a Data Scientist at Arag Legal Insurance, you play a pivotal role in transforming data into actionable insights that drive business decisions and enhance customer experiences. This position is central to the company's mission of providing innovative legal solutions by leveraging data analytics, predictive modeling, and machine learning techniques. By analyzing complex datasets, you will contribute to the development of products that empower users to navigate legal challenges more effectively.

Most of the loop measures decision-making under uncertainty rather than recall. You are scored on whether you state your assumptions, commit to an estimate you can defend, and say explicitly what evidence would change it.

Focus areas

  • Reconcile amounts in minor units and currency
  • Separate authorization, settlement and dispute outcomes cleanly
  • Decompose expected loss into PD, LGD, EAD

Overview

Your work will directly impact various facets of the business, from optimizing operational efficiency to improving client satisfaction. You will collaborate with cross-functional teams, including product managers, engineers, and legal experts, to solve real-world problems and create data-driven solutions. This dynamic role not only presents challenges but also offers opportunities to influence the strategic direction of Arag Legal Insurance and its offerings in the legal insurance market.

The Arag Legal Insurance interview process

Arag Legal Insurance candidates report 3 rounds · ≈ 3-5 weeks. The stages below are what candidates describe, not a published process.

Initial Screening

Data Scientist covers at least four different jobs: experimentation, product analytics, causal work on observational data, and applied modelling that ships into a system. A screening call is the cheapest place to find out which of them is being hired for, and doing that diagnosis openly reads as senior rather than fussy. Ask what the last few pieces of work on the team actually were, and roughly how a week splits between querying, modelling and stakeholder time. Then say which parts of that you have done and which you have not. Claiming the whole range is the fastest way to be caught one round later.

What to demonstrate

  • Whether you can distinguish the flavours of the role and locate your own experience inside one of them honestly
  • Whether you name what you have not done instead of stretching to cover every line of the posting
  • Whether your hard constraints (notice period, location, work authorisation, level) surface now rather than at offer stage

How to prepare

  • Map the last two years of your time into rough percentages across query writing, experiment design, modelling and stakeholder work, so a question about scope has a real answer
  • Mark every responsibility in the posting as done, adjacent or new, and prepare one sentence for each adjacent item naming the closest thing you have actually built
  • Decide which logistics are non-negotiable before the call so you can state them in one sentence rather than negotiating live

Technical Interviews

Before anything else, this round is a reading test. You are given a small schema and a question phrased in business language, and most of the difficulty sits in the gap between them. Who counts as an active user, does a refunded order still count as an order, is that date column an event time or a load time. Weak answers start typing immediately and compute something precise about the wrong population. Strong ones pin the definition in one sentence, name the column that encodes it, then write the query. On a timed assessment with nobody to tell, write the definition in a comment anyway.

What to demonstrate

  • Whether an ambiguous term becomes a specific column and filter before any computation happens
  • Whether you read the schema for keys and cardinality rather than only for column names
  • Whether the result answers the question at the grain it was asked at, per user or per session or per day

How to prepare

  • Take three metrics you already use and write down the exact filter and exact grain behind each, then practise stating one of them in a single sentence out loud
  • On a schema you have never seen, spend the first minute writing what one row of each table means and which key it is unique on, then predict which joins can duplicate rows
  • Rehearse a version where the definition changes halfway through, and edit the query you have instead of starting over

Collaborative Assessment

A handful of shapes account for most of what gets asked in this format: a ranking or deduplication inside groups, a running or rolling total, a period-over-period comparison, and a cohort tracked forward over time. Recognising the shape quickly is most of the speed here; deriving it from scratch while a clock runs is where the time goes. Know that a window function keeps every row while a GROUP BY collapses them, and know which one the question needs. If the exercise is in Python instead of SQL, the same shapes arrive as groupby with transform, shift and merge, and the same grain mistakes are available.

What to demonstrate

  • Whether you reach the right construct without a detour, such as ROW_NUMBER over a partition to deduplicate instead of a self-join against a MAX subquery
  • Whether you know what your window frame actually is, since adding ORDER BY inside OVER changes the default frame and silently changes a running total
  • Whether the thing runs. A near-miss that throws an error scores below a plainer query that returns the right rows.

How to prepare

  • Write each of the four shapes once from memory against a small schema and keep the working version somewhere you will reread it: dedupe with ROW_NUMBER, a running total, a month-over-month change with LAG, and a retention table
  • Compute one running total twice on data with tied timestamps, once on the default frame and once with ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW, and look at where the two disagree
  • If Python is on the table, rebuild the dedupe and the running total with groupby and cumsum, then assert the two implementations return identical rows

Where candidates lose points

Averaging delinquency across a book that is growing

A loan three months old cannot be 90 days past due, so a portfolio with many recent originations reports a low blended 90+ rate purely from age mix. The blended rate falls fastest exactly when originations grow fastest, which is precisely when credit quality most needs watching, so the metric moves in the reassuring direction during the riskiest period. Only comparisons at equal months on book are valid, which is what a vintage or roll-rate view enforces.

Recalibrating an underwriting cutoff on approved and funded applicants only

Rejected applicants have no repayment outcome, and they were rejected because the incumbent model scored them badly, so the missingness depends directly on the outcome being modelled. Reject inference by augmentation or parcelling fills the gap using the incumbent model's own assumptions, which means it can confirm those assumptions but cannot test them. The only genuinely new information about the reject region comes from bureau performance on rejects who borrowed elsewhere, or from a deliberately randomised approval band around the cutoff.

Reporting a p-value with no effect size or interval

Give the estimated difference with a confidence interval in the units the business cares about, then say whether that whole interval is worth acting on. A p-value only addresses whether you can rule out exactly zero; it says nothing about magnitude.

Ending an analysis without a recommendation or next step

Close with what you would do and what would change your mind, stated as a condition you can check later. If the evidence is genuinely inconclusive, recommend the specific next measurement and say what it costs in time or exposure.

Questions & practice

Write a function to calculate the Pearson correlation coefficient between two lists of numbers.

Medium · statistics and probability

Approach

  1. Quantify uncertainty explicitly rather than reporting a point estimate alone.
  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

  • Which assumption here is most likely to be violated in practice?
  • How would you explain this result to someone who does not know statistics?

How would you implement a logistic regression model from scratch?

Medium · machine learning and modelling

Approach

  1. Set a baseline first, so any model has something honest to beat.
  2. Frame the prediction: the label, the moment of prediction, and the action it triggers.
  3. Pick an evaluation metric that matches the cost of each error type, not a default.

Follow-up

  • Where could label leakage enter this setup?
  • How would you choose the decision threshold, and who owns that choice?

What is regularization, and why is it important in machine learning?

Medium · machine learning and modelling

Approach

  1. Frame the prediction: the label, the moment of prediction, and the action it triggers.
  2. Pick an evaluation metric that matches the cost of each error type, not a default.
  3. Say how the offline result would be validated online before it is trusted.

Follow-up

  • Where could label leakage enter this setup?
  • What would you monitor after launch to know the model is still valid?

Build a vintage delinquency table without pivot or unstack

Easy · vintage analysis · cohorts · groupby · cumulative max

fct_loan_performance_monthly gives loan_id, origination_month, months_on_book, days_past_due, charge_off_flag and restructured_flag. Produce a DataFrame with one row per origination_month and columns for months_on_book 0 through 12, each cell holding the share of that vintage's funded loans that had ever reached 90 or more days past due, or charge-off, by that age. You may not use pivot, pivot_table, crosstab or unstack. Cells for ages a cohort has not yet reached must be NaN rather than zero.

Approach

  1. Define the per-row indicator as days_past_due >= 90 or charge_off_flag, then take a cumulative maximum of it per loan ordered by months_on_book, because the metric is reached-by-age-m, not in-that-state-at-age-m.
  2. Deal with restructuring before the cumulative max. Restructuring resets days_past_due, so a restructured loan re-enters at current and, without the cumulative maximum carrying its pre-restructure worst state, reads as a cure.
  3. Fix the denominator once as the count of distinct loan_id per origination_month across the whole cohort. Prepaid and charged-off loans stop producing rows, so a denominator recomputed at each age silently shrinks exactly where losses land.
  4. Aggregate with groupby(['origination_month','months_on_book'])['ever_90'].sum(), then pre-build the output frame indexed by sorted origination months with integer columns 0 to 12 and assign from the grouped Series by .loc on its index.
  5. Mask cells beyond each cohort's maximum observed months_on_book so an immature cell reads NaN instead of an artificially low rate.

Worked solution (30 min)

  1. Sort by loan_id and months_on_book, build the ever_90 indicator, then apply groupby('loan_id')['ever_90'].cummax().
  2. Compute cohort_size as the distinct loan_id count per origination_month, before any filtering on age.
  3. Group the cumulative indicator by origination_month and months_on_book and sum it to get the numerator per cell.
  4. Create the output frame with the sorted origination months as index and range(0, 13) as columns, fill it from the grouped Series, and divide each row by its cohort_size.
  5. Compute each cohort's maximum observed months_on_book and set every cell to the right of it to NaN.

Expected result: A DataFrame with one row per origination_month and columns 0 to 12, values non-decreasing left to right within every row, near zero in column 0, and NaN forming an upper-right triangle where cohorts have not yet aged.

Verify it yourself

  • Every row is non-decreasing across columns; a decrease means the cumulative maximum was not applied or a restructure reset leaked through.
  • The denominator per row equals the cohort's distinct loan count and does not change across columns.
  • Column 0 is at or near zero for every vintage, since a loan cannot be 90 days past due at its first month end.
  • origination_month plus months_on_book is constant along an anti-diagonal, so one anti-diagonal should reproduce a direct calendar-month filter.

Follow-up

  • Two adjacent vintages diverge at months_on_book 6. How would you separate seasoning, mix shift and a genuine credit-quality change?
  • The three most recent vintages look best on this table. What do you check before saying so?
  • How does the table change if charge-off policy moved from 180 to 120 days past due partway through the series?

Vintage ninety-plus rate at twelve months on book

Medium · vintage analysis · window functions · right censoring

From fct_loan_performance_monthly, build a vintage table keyed on origination_month: the share of each cohort that ever reached days_past_due of 90 or more, or charge_off_flag = true, at or before months_on_book = 12. Restructuring resets days_past_due, so for any loan with restructured_flag true, evaluate only the month ends strictly before its first restructured month. Return origination_month, loans_funded, bad_loans and bad_rate. Exclude any cohort that does not yet have a months_on_book = 12 observation for every loan still on book.

Approach

  1. Establish the cohort denominator from the first month end each loan appears at, months_on_book = 0, so a loan is counted once in its origination_month rather than once per monthly row.
  2. Find each loan's first restructured month with MIN(as_of_month_end) FILTER (WHERE restructured_flag) OVER (PARTITION BY loan_id), or the equivalent grouped subquery, and keep it null for loans never restructured.
  3. Flag a loan bad if any row with months_on_book <= 12 and as_of_month_end earlier than that first restructured month has days_past_due >= 90 or charge_off_flag = true, which is what 'pre-restructure worst state' means in practice.
  4. Gate maturity by requiring the cohort's newest month end to be at least 12 months after origination_month, and report immature cohorts as incomplete rather than letting them appear at a flattering low rate.
  5. Aggregate to one row per origination_month and read the column downward, not across calendar time, because the whole point is comparing cohorts at equal age.

Worked solution (35 min)

  1. CTE 1: per loan_id, derive origination_month, the first restructured month end, and the maximum months_on_book observed.
  2. CTE 2: join back to the monthly rows, filter to months_on_book <= 12 and to month ends before any restructure, then flag bad with a BOOL_OR.
  3. CTE 3: aggregate to origination_month with COUNT() as loans_funded and COUNT() FILTER (WHERE is_bad) as bad_loans.
  4. Apply the maturity gate and compute bad_rate with a numeric cast.

Expected result: One row per matured origination_month with loans_funded, bad_loans and a bad_rate between 0 and 1. The most recent immature cohorts are absent from the output entirely rather than present with a small bad_rate.

Verify it yourself

  • SUM(loans_funded) across reported cohorts equals COUNT(DISTINCT loan_id) restricted to those same origination months.
  • Recomputing without the months_on_book cap raises bad_rate monotonically for every cohort, and raises it most for the oldest, which is the seasoning effect made visible.
  • No cohort in the output has a maximum months_on_book below 12.

Follow-up

  • Should a restructure inside 12 months count as bad in its own right? Argue both sides and say what you would actually ship.
  • A loan that prepaid in full at month 4 never had a chance to go 90 days past due. In or out of the denominator, and why?
  • The 2025-11 cohort is two points worse at month 12 than its neighbours. What three queries do you run before you call it a credit-quality change?

Attribute chargebacks to transaction month without fanning out

Medium · fan-out · cohort attribution · maturity

Report the matured first-chargeback rate. Numerator: fct_card_dispute rows whose dispute_stage is first_chargeback, representment, pre_arbitration or arbitration, attributed to the requested_at month of the linked fct_payment_authorization row rather than to opened_at. Denominator: settled authorizations in that same transaction month, meaning settled_at is not null and is_reversal is false. One authorization can carry more than one dispute case. Report only transaction months whose last day is at least 120 days old, and mark the remainder incomplete rather than showing them as low.

Approach

  1. Compute the denominator from fct_payment_authorization alone, grouped by the requested_at month, before any dispute table is mentioned, so the join cannot touch it.
  2. Compute the numerator as a separate aggregate: join disputes to their authorization only to recover requested_at, then count dispute rows per transaction month with the stage filter.
  3. Join the two aggregates on the month key, which keeps the grain at one row per month and makes double counting structurally impossible rather than something you have to remember.
  4. Apply the maturity gate on the month's last day plus 120 days against the current date, because a transaction on the final day of the month is the least mature one in the cohort.
  5. Emit an explicit status column of 'final' or 'incomplete' instead of filtering immature months away silently, so a reader cannot mistake absence for zero.

Follow-up

  • Should the numerator count dispute cases or disputed authorizations? Which one reconciles to the loss line, and which one to the operations queue?
  • Some reason codes allow filing well beyond 120 days. How would you estimate the tail on a month you have decided to call final?
  • How would you present the incomplete months so that a weekly reader does not read the right-hand slope as an improvement?

Given a dataset with customer information, how would you approach predicting customer churn?

Medium · product sense and metrics

Approach

  1. Name one primary metric, then the guardrail that stops it being gamed.
  2. Fix the population and the time window before naming any metric.
  3. State what result would change your recommendation, so the answer is falsifiable.

Follow-up

  • What would you do if the primary metric and the guardrail moved in opposite directions?
  • Which segment would you cut first, and what would that rule out?

What steps would you take to analyze the impact of a legal policy change on customer claims?

Medium · product sense and metrics

Approach

  1. Decompose the metric into the rates that drive it, and say which one you would check first.
  2. Restate the decision this analysis has to support, and who acts on the answer.
  3. Fix the population and the time window before naming any metric.

Follow-up

  • What would you do if the primary metric and the guardrail moved in opposite directions?
  • Which segment would you cut first, and what would that rule out?

Describe how you would identify and mitigate bias in a data-driven decision-making process.

Medium · product sense and metrics

Approach

  1. Decompose the metric into the rates that drive it, and say which one you would check first.
  2. Restate the decision this analysis has to support, and who acts on the answer.
  3. State what result would change your recommendation, so the answer is falsifiable.

Follow-up

  • Which segment would you cut first, and what would that rule out?
  • How would you detect that the metric is being gamed rather than genuinely improving?

How do you prioritize tasks when working on multiple projects with tight deadlines?

Medium · product sense and metrics

Approach

  1. State what result would change your recommendation, so the answer is falsifiable.
  2. Restate the decision this analysis has to support, and who acts on the answer.
  3. Decompose the metric into the rates that drive it, and say which one you would check first.

Follow-up

  • Which segment would you cut first, and what would that rule out?
  • How would you detect that the metric is being gamed rather than genuinely improving?

How would you design an A/B test to measure the effectiveness of a new product feature?

Medium · a/b testing and experimentation

Approach

  1. Name the randomisation unit first; it decides the variance and what the test can detect.
  2. Say whether units interfere with each other, and switch design if they do.
  3. Decide the analysis before seeing data, including how long it runs and when you look.

Follow-up

  • What would you do if you could not randomise at all?
  • What would you conclude if the result is positive but the test is underpowered?

What methods would you use to handle missing data in a dataset?

Medium

Approach

  1. State your assumptions explicitly before working the problem.
  2. Clarify what is being asked and what a complete answer would contain.
  3. Work from the decision backwards to the evidence you would need.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Diagnose a sample ratio mismatch before reading the result

Easy · sample ratio mismatch · instrumentation · chi-square

A two-week test of a new risk rule logged 512,340 exposures in treatment and 508,110 in control against an intended 50/50 split. The dashboard reports a 1.8 percent relative lift in the count-weighted authorization approval rate, p equals 0.004. Exposures are written by the events pipeline at the point the rule is evaluated. Before anyone reads the lift, test whether the split is consistent with 50/50, state your verdict, rank the mechanisms that would produce this imbalance, and say what you do with the two weeks of data.

Approach

  1. Run the test rather than eyeballing the ratio: a chi-square goodness-of-fit on one degree of freedom against the expected 50/50, or equivalently a binomial test on the treatment share. A 0.42 percent imbalance looks trivial and is not, because at a million exposures the null distribution is extremely tight.
  2. Declare the result uninterpretable rather than adjusting it. An SRM means units are missing from one arm conditional on something, and the something is usually correlated with the outcome, so reweighting or trimming does not restore exchangeability; it just hides the selection.
  3. Localise the mismatch before hypothesising about it: recompute the split by day, by channel, by issuer_country and by whether the rule actually fired. An SRM confined to one slice points straight at the code path that produced it.
  4. Rank mechanisms by how often they are the cause here. First, exposure logged downstream of a step the treatment changes, so any arm-specific drop-off before the log line silently deletes units. Second, assignment keyed on something mutable or nullable, such as card_token_id across a reissue or a null customer_id on guest traffic. Third, bot or fraud filtering applied after assignment and hitting arms unequally. Fourth, retry rows deduplicated after assignment rather than before. Fifth, a ramp or a rollback that moved mid-test.
  5. Close the loop with an A/A run on the fixed pipeline before rerunning the A/B, and add a continuous SRM check with an alert threshold so the next occurrence is caught on day one instead of at readout.

Worked solution (15 min)

  1. Total exposures N = 1,020,450, so expected per arm E = 510,225 and the absolute deviation is 2,115 in each direction.
  2. Chi-square = 2 * 2115^2 / 510225 = 2 * 4,473,225 / 510,225 = 2 * 8.767 = 17.53 on one degree of freedom.
  3. Convert: sqrt(17.53) = 4.19 standard deviations, so p is about 3e-5. The observed treatment share is 0.50208 against a null standard error of 0.000495, which is the same statement in another form.
  4. Declare SRM, withhold the 1.8 percent lift from any decision, and produce the per-day and per-channel split table that localises the cause.

Expected result: Chi-square is about 17.5 on one degree of freedom, p is about 3e-5. This is a sample ratio mismatch. The correct output is a defect report with a localisation table, not a treatment effect; the 1.8 percent lift is not reported as a result even with a caveat.

Verify it yourself

  • The binomial standard error of the treatment share is sqrt(0.25 / 1020450) = 4.95e-4; the observed share 0.50208 sits 4.19 standard errors from 0.5, matching the chi-square.
  • Re-running the same test on the assignment log rather than the exposure log should show a clean 50/50 if the randomiser is sound and the loss is downstream, which immediately narrows the search.
  • Summing the per-day chi-square contributions should reproduce the total; a single day dominating the sum is a deploy, not a design flaw.

Follow-up

  • Suppose the mismatch is entirely in one issuer_country and the treatment adds a 3-D Secure step there. What is the most likely code path, and what does that imply about the sign of the observed lift?
  • What SRM alert threshold would you set for a daily check, and how do you keep it from firing constantly across many concurrent tests?
  • If the split is exactly 50/50 but the two arms have different distributions of mcc and channel, is that an SRM? What is it, and what do you do about it?

Portfolio delinquency improving while the loan book doubles

Easy · vintage analysis · age mix · right censoring

The blended 90-plus days-past-due rate across fct_loan_performance_monthly fell from 3.1 to 2.2 percent over two quarters while monthly funded volume roughly doubled. Credit leadership wants to know whether underwriting improved. Columns: loan_id, as_of_month_end, origination_month, months_on_book, original_principal_minor, principal_balance_minor, days_past_due, delinquency_bucket, restructured_flag, charge_off_flag, charge_off_date. Produce the view that answers the question honestly, and state in one sentence what the blended rate can and cannot tell you.

Approach

  1. Name the mechanical floor first. A first instalment falls due roughly a month after funding, so a loan cannot reach dpd_90_plus until around its fourth month on book. Every recent origination therefore enters the denominator with a numerator that is structurally zero.
  2. Build a vintage table: rows origination_month, columns months_on_book, cell equal to the share of that cohort whose worst days_past_due reached 90 or more, or whose charge_off_flag became true, at or before that age.
  3. Use each loan's worst state to date rather than its current bucket, and take the pre-restructure worst state, because restructuring resets days_past_due and would otherwise read as a cure.
  4. Compare cohorts only at equal months_on_book, and render cells beyond a cohort's current maturity as absent rather than zero, so the table cannot be misread left to right.
  5. Decompose the blended move into an age-mix component and a within-age component, so the write-up states how much of the 0.9 point improvement is arithmetic rather than asserting it.

Follow-up

  • What does the diagonal of a vintage table represent, and when is reading it the right thing to do?
  • How would a change in charge-off timing policy show up in this table, and how would you separate it from credit quality?
  • Which single chart goes in front of the credit committee, and what do you say when someone asks for the blended series anyway?

Suggested practice checklist

Instead of guessing where the week should go, day one measures it under a fixed rubric and allocates the remaining hours in proportion to the gaps. The method is deliberately rigid: the allocation is written down before any studying starts and is not renegotiated when a topic turns out to be unpleasant.

Day 1 — Diagnostic, scored before you study anything

  • Sit a 100-minute timed diagnostic in four blocks: 30 minutes of SQL across three prompts, 25 minutes of short-answer statistics, 25 minutes on one modelling or case prompt, and 20 minutes delivering one behavioural story aloud.
  • Score each block from 0 to 3 on a fixed rubric where 3 is correct and fluent, 2 is correct but slow or prompted, 1 is partially correct, and 0 is stuck, grading the output rather than how the attempt felt.
  • Allocate the hours for days two to five roughly in proportion to 3 minus the score in each block, write the allocation down, and commit to not revising it midweek.

Deliverable: A scored rubric and a fixed hour allocation for the rest of the week.

Day 2 — Largest gap: find the boundary rather than the subject

  • Break the weakest area into five named sub-skills (for query work: grain control, window frames, date arithmetic, set logic with NULLs, and reading a query plan) and rate each one, so the rest of the week targets a sub-skill instead of a subject.
  • Solve three problems chosen to sit just above where the rating drops off, and for each write the first move you failed to make.
  • Re-solve one of them from memory four hours later, on paper, with nothing open.

Deliverable: A five-item sub-skill map with the two blocking sub-skills circled.

Day 3 — Largest gap: drill the blocking sub-skill

  • Do eight short repetitions of the same shape rather than eight different problems, so what you practise is the pattern and not the puzzle.
  • Write the rule you now hold in one sentence, then test it against a case built to break it: a ranking function over a column with ties, or a two-sample test on observations that are obviously dependent.
  • Have someone else read your one-sentence rule and find the precondition you left out.

Deliverable: One rule statement with its preconditions attached and one counterexample that would have caught the incomplete version.

Day 4 — Second gap, plus maintenance on your strongest area

  • Run the same sub-skill map and boundary protocol on the second-largest gap, compressed into half the day.
  • Spend 25 timed minutes on your strongest area to stop it decaying, choosing the hardest problem you can still finish rather than an easy warm-up.
  • Compare how the two areas fail: whether you lose time on recall, on setup, or on arithmetic, because the fix differs for each.

Deliverable: A second sub-skill map plus a one-line diagnosis of how each area fails you.

Day 5 — The gap that is not a skill

  • Record yourself answering one technical and one behavioural prompt, then count two things in the playback: how many seconds before your first clarifying question, and how many sentences you started without knowing where they ended.
  • Rewrite your three most-used stock phrases into shorter versions, and practise saying "I do not know, here is how I would find out" without softening it into a guess.
  • Deliver one answer again with a hard 90-second limit to force structure before detail.

Deliverable: Two recordings with a counted improvement in time-to-first-question.

Day 6 — Retest under day-one conditions

  • Sit the same 100-minute diagnostic structure with new prompts of comparable difficulty and score it on the identical rubric.
  • Compare block by block, and for any block that did not move, change the method rather than adding hours: a block stuck at 1 usually means the practice was too varied, not too short.
  • Write which single block you would still lose the offer on.

Deliverable: A second scored rubric placed next to the first, with one named remaining risk.

Day 7 — Full loop under interview conditions

  • Run a 60-minute mock covering the two blocks that moved least, with an interviewer instructed to interrupt and change direction.
  • Write your recovery script for the moment you go blank: restate the question, state your assumption, name the first thing you would check.
  • Reduce the week to the rule statements you wrote, each with its preconditions attached, then say every one of them out loud without reading it and cut any you cannot state in a single sentence, since a rule you have to reconstruct mid-answer will not survive being interrupted.

Deliverable: A one-page card holding the recovery script and only the rules you could state from memory.

Bring numbers, including the ones you are unsure of

An answer without a quantity is hard to interrogate, so interviewers keep probing until they find one. Come with the baseline, the change, the window it was measured over, and how confident you were. If the effect never got measured, say so and say what you would have measured. Fabricated precision is worse than an honest gap.

How do you handle constructive criticism regarding your work?

Medium · behavioural and stakeholder questions

Approach

  1. Close with what you would do differently, concretely.
  2. State the situation in two sentences and spend the rest on your reasoning.
  3. Quantify the outcome, including what you would not claim credit for.

Follow-up

  • How did you know the outcome was caused by your change?
  • What would you do differently if you ran that project again?

Allocate one analyst-week across three competing risk requests

Medium · prioritisation · decision deadlines · stakeholder negotiation

Three requests land in the same week and you have one analyst-week. Payments wants a merchant-level decline teardown before a contract renewal in nine days. Credit wants a swap-set analysis on a cutoff change scheduled to ship in six weeks. Insurance wants accident-quarter loss ratios at 12 months development for a reserving review with no fixed date. Each sponsor believes theirs is first, and each has escalated before. Produce the allocation, the reasoning you would say out loud to all three at once, and what you explicitly drop.

Approach

  1. Score each request on the decision it unblocks rather than on effort or on how loudly it arrived: what changes if it is late, and is that change reversible.
  2. Separate deadline from value. The nine-day renewal is a hard, irreversible date with a bounded prize; the six-week cutoff has slack but a much larger downside if it ships unmeasured; the reserving number has no date but feeds external reporting, which is its own kind of hard.
  3. Hunt for the cheap partial in each: a decline teardown restricted to the top merchants by declined value usually answers the contract question at a fraction of the full cut.
  4. Sequence by hard date first, then by largest irreversible downside, and deliver the trade-off to all three sponsors in one message rather than three, so nobody negotiates privately against a version you told someone else.
  5. Name what is dropped and who now owns that consequence, in writing, so the trade-off is visible rather than silently absorbed by you.

Follow-up

  • The credit sponsor escalates to your manager. What do you change, and what do you refuse to change?
  • How would you make this allocation reproducible so the next contested week is a rule application rather than a negotiation?

Turn a one-line fraud-number request into a scoped brief

Easy · scoping · metric definition · denominators

A stakeholder messages: what is our fraud rate, and is it going up? You have fct_payment_authorization, fct_card_dispute and dim_customer. At least four defensible answers exist: count-weighted or value-weighted, attributed to the transaction month or to the dispute filing month, and gross or net of recoveries and successful representments. You get one reply before someone else produces an uncaveated number. Write that reply: the clarifying questions you ask, the single default you will produce if nobody answers, and what the default excludes.

Approach

  1. Establish the decision behind the question first, because a risk-rule change, a board number and a merchant contract negotiation need different denominators, and asking which one is not stalling.
  2. Offer a short menu rather than an open question: a stakeholder can choose between two named options but cannot specify a denominator from scratch.
  3. Commit to a default so the reply is useful even if nobody answers, for example net fraud loss in basis points of settled volume, attributed to the requested_at month, matured months only.
  4. State the exclusions in the same breath as the default: non-fraud dispute categories, transaction months with less than 120 days of maturity, and first-party abuse that arrives coded as consumer_dispute.
  5. Give a delivery time for the default and a longer one for the fuller cut, so the choice between them carries a visible cost.

Follow-up

  • They come back wanting it by merchant for a contract negotiation. What changes in the definition and in the maturity rule?
  • How would you separate first-party abuse from third-party fraud in this data, and what would you refuse to conclude from the split?