Aman · Data Scientist
Updated · 2026-09-24

Aman Data Scientist
Interview Questions & Guide 2026

THE 60-SECOND BRIEF

As a Data Scientist at Aman, you are at the intersection of complex data ecosystems and high-impact product decision-making. Your role is critical to the company’s ability to turn raw data into actionable intelligence that drives user growth, operational efficiency, and product innovation. You will be expected to act as a bridge between technical complexity and business strategy, ensuring that every model, experiment, and metric you design serves the broader goals of the organization.

Ask early whether the loop includes an asynchronous take-home or a timed live case, because the two are graded on different things. A take-home is read as an artifact: the question you decided to answer, what you did about missing or malformed records, and a conclusion stated plainly enough for someone to act on. A reviewer who cannot rerun your notebook discounts the result whatever score is printed in it. Hold to the stated time box and write down what you would have done with more of it, since the follow-up round is usually a live defence of the same work.

Aman candidates report 2 rounds · ≈ 2-4 weeks. The stages below are what candidates describe, not a published process.

Reconcile amounts in minor units and currencySeparate authorization, settlement and dispute outcomes cleanlySet fraud thresholds by expected cost

30 min read

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See the practice prompts

15Practice promptsAcross five skill areas
3With worked solutionsIncluded in the practice prompts

As a Data Scientist at Aman, you are at the intersection of complex data ecosystems and high-impact product decision-making. Your role is critical to the company’s ability to turn raw data into actionable intelligence that drives user growth, operational efficiency, and product innovation. You will be expected to act as a bridge between technical complexity and business strategy, ensuring that every model, experiment, and metric you design serves the broader goals of the organization.

The work at Aman is characterized by both scale and ambiguity. You will likely find yourself tackling challenges related to product metric design, diagnosing sudden drops in key performance indicators, and running rigorous A/B tests to validate product hypotheses. Because this is a product-biased Data Scientist role, you will not just be building models; you will be influencing the "why" and "how" behind product features, requiring a sharp analytical mind and a deep understanding of statistical foundations.

01

Technical Screening

reported

Much of what gets scored here happens out loud while you type. Nobody can see your reasoning inside a half-written query, so five silent minutes read as being stuck even when they are not. State the plan in plain language first: which tables, what grain you are aggregating to, and the one filter that defines the population. Then write it. The narration doubles as insurance, because a wrong plan gets caught early and cheaply while a wrong query gets caught at the end with no time left to redo it. A timed statistics section, where one exists, is a separate test with its own clock.

What to demonstrate

  • Whether the query you write matches the plan you just described
  • What you do with a hint, meaning whether the correction gets absorbed or the first approach gets defended
  • Whether you can debug your own wrong output by reading the result set and naming which part of the query produced the anomaly

How to prepare

  • Solve three problems while screen-sharing into a recording, then watch it back and mark every stretch longer than thirty seconds where you said nothing
  • Practise compressing the plan into one sentence before typing, then check afterwards whether the finished query actually matched it
  • Time yourself on statistics questions that carry a business reading, such as what a confidence interval does and does not claim, rather than re-reading notes without a clock
PracHub interview research ↗
02

Use Case Assessment

reported

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
PracHub interview research ↗

PracHub editorial advice for the preparation topics above.

01

Counting authorizations instead of weighting them, and summing amounts across currencies

Declines skew toward high-value, cross-border and card-not-present transactions, so an unweighted approval rate can sit flat while approved value falls. Merchant retry logic also turns one declined purchase into several rows, inflating the denominator by an amount that varies by merchant and by decline reason. Amounts are held in the minor unit of the transaction currency and that unit is not always two decimals, since some currencies have none and some have three, so summing amount_minor across currencies produces a figure with no interpretation at all.

02

Reading the most recent months of fraud and dispute rates as final

Consumer dispute rights commonly run around 120 days from the transaction or expected delivery date, and several reason codes run considerably longer, so the disputes belonging to a recent transaction month have simply not been filed yet. Any chart attributed by transaction date therefore slopes down at the right edge regardless of what is happening. The fix is to report only matured cohorts, or to apply development factors estimated from completed months and to show the estimate as an estimate.

03

Reaching for a model before the target metric exists

Before naming an algorithm, write down the label, the prediction time, and the action that changes when the score crosses a threshold. If you cannot say what decision the output drives, any modelling choice is guesswork dressed up as method.

04

Dropping rows with missing values without naming the mechanism

Say whether the values are missing at random, missing by a known process, or missing in a way that depends on the outcome, and handle them accordingly. Deleting incomplete rows silently redefines the population whenever missingness correlates with what you are measuring.

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

12 technical prompts3 include a worked solution

Describe the conditions under which you would choose a non-parametric …

medium
statistics and probability

Describe the conditions under which you would choose a non-parametric test over a t-test.

Approach
  1. Say what the estimate is of, and over what population it generalises.
  2. Translate the result into the decision it informs, in one plain sentence.
  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 does a decision tree handle non-linear relationships in data?

medium
machine learning and modelling

How does a decision tree handle non-linear relationships in data?

Approach
  1. Frame the prediction: the label, the moment of prediction, and the action it triggers.
  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?

Write integrity checks for the authorization and settlement lifecycle

easyWorked solution
data qualityminor unitsfx reconciliation

You are given fct_payment_authorization as a pandas DataFrame with auth_id, requested_at, amount_minor, transaction_currency, auth_result, decline_reason_code, is_reversal, parent_auth_id, captured_at, captured_amount_minor, settled_at, settlement_amount_minor, settlement_currency and settlement_fx_rate. Write a function returning one row per integrity check with the check name, failing row count, failing share and up to five example auth_id values. Cover at least six checks, one of which reconciles captured_amount_minor against settlement_amount_minor through settlement_fx_rate. Partial capture, zero-amount verification and a decline with no capture are all legitimate and must not be flagged.

Approach
  1. Separate contract violations from observations before writing any code: an approved row carrying a decline_reason_code is structurally impossible, while a capture two days after requested_at is merely slow and belongs in a different severity tier.
  2. Express each check as a boolean mask over the whole frame and collect the masks in a dict, so the summary table is one comprehension over mask.sum() rather than a row loop.
  3. For the reconciliation, leave minor units before comparing: expected = captured_amount_minor / 10exponent[transaction_currency] * settlement_fx_rate * 10exponent[settlement_currency]. Build the exponent table covering zero-decimal and three-decimal currencies instead of assuming two everywhere.
  4. Guard the legitimate cases explicitly so each mask fires only on the genuine contradiction: captured_amount_minor below amount_minor is partial capture, amount_minor of zero on an approved row is account verification, a null captured_at on a declined row is correct.
  5. Sort the output by failing share times a stated severity weight, because a check firing on 0.01 percent of rows can still be the one that breaks a ledger reconciliation.
Worked solution 25 min
  1. Assert auth_id is unique, then build a currency exponent lookup that includes the zero-decimal and three-decimal currencies present in the data.
  2. Define masks for: approved with non-null decline_reason_code; declined with non-null captured_at; captured_amount_minor above amount_minor with parent_auth_id null; captured_at before requested_at; settled_at before captured_at; is_reversal true with parent_auth_id null; settlement_currency differing from transaction_currency while settlement_fx_rate is null.
  3. Add the exponent-aware reconciliation mask with a tolerance of one minor unit plus a small relative term.
  4. Assemble a frame of check_name, n_failing, pct_failing and up to five sample auth_id values, ordered by severity then share.
  5. Read five flagged rows per check by hand and confirm each is genuinely contradictory before reporting any counts.
EXPECTED RESULTA DataFrame of at least eight rows, one per check, each with n_failing, pct_failing and example auth_id values. The reconciliation check should fire on a whole currency at once rather than on scattered rows, because an exponent error is systematic while an FX error is not.
Follow-up
  • Which of these would you run as a blocking pipeline assertion and which as a monitored metric, and why?
  • The FX check fails on 3 percent of rows, all in one settlement currency. How do you decide between a data bug and a rounding convention?
  • How would you detect that a currency's minor-unit exponent is wrong in your reference table, using only the transaction data?

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.

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
01Diagnostic, 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.

Practice prompt ↗Practice prompt ↗Practice prompt ↗Worked solution ↗
02Largest 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.

Practice prompt ↗Practice prompt ↗
03Largest 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.

Practice prompt ↗Practice prompt ↗
04Second 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.

Practice prompt ↗Practice prompt ↗Worked solution ↗
05The 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.

Practice prompt ↗Practice prompt ↗
06Retest 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.

Practice prompt ↗Practice prompt ↗
07Full 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.

Practice prompt ↗Practice prompt ↗Worked solution ↗

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

Half of this section is about translation. Be ready to describe how you explained a result to someone who did not want the method, only the implication, and what you did when the simplified version started being repeated in a way that overstated it. Correcting your own simplification is a strong beat.

Tell me about a time you had to resolve a conflict within your team re…

medium
behavioural and stakeholder questions

Tell me about a time you had to resolve a conflict within your team regarding a technical approach.

Approach
  1. State the situation in two sentences and spend the rest on your reasoning.
  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?

Allocate one analyst-week across three competing risk requests

medium
prioritisationdecision deadlinesstakeholder 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?

Explain an incomplete dispute chart to a non-technical executive

easy
dispute maturitystakeholder communicationright-censoring

A finance lead is looking at first-chargeback rate by transaction month, built from fct_card_dispute joined to fct_payment_authorization on auth_id and attributed to requested_at. The last three months slope sharply down and the lead wants to announce a fraud improvement at tomorrow's review. Consumer dispute rights commonly run around 120 days from the transaction or expected delivery date, so those months are not complete. In five minutes, with no statistics vocabulary, explain why the decline is not yet evidence and say exactly what you would put on the slide instead.

Approach
  1. Lead with the mechanism in the listener's own terms, not with the statistical name for it: a dispute is attributed to the month the transaction happened, but it can be filed up to roughly 120 days later, so recent months contain only the disputes filed so far.
  2. Show completeness rather than arguing about the rate: for each transaction month, plot the share of its eventual disputes already filed, estimated from months that are fully matured. The last three months will sit visibly below 100 percent.
  3. Replace the chart with two artefacts: a matured series that stops 120 days back and is labelled final, and a development-factor estimate for the immature months drawn as a dashed range and labelled an estimate.
  4. Hand over one sentence the executive can repeat without you in the room: the recent months look better because the disputes have not arrived yet, not because fewer will arrive.
  5. Offer a weekly signal they can watch instead, such as the risk-score mix of approved volume or the decline-rule hit rate, and state up front what it does and does not predict.
Follow-up
  • The deck ships tomorrow regardless. What exactly goes on the slide, and what wording do you insist on?
  • How would you estimate the development factors, and how would you notice if they had shifted?
  • 01

    Tell me about a time you had to resolve a conflict within your team regarding a technical approach.

  • 02

    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.

  • 03

    A finance lead is looking at first-chargeback rate by transaction month, built from fct_card_dispute joined to fct_payment_authorization on auth_id and attributed to requested_at. The last three months slope sharply down and the lead wants to announce a fraud improvement at tomorrow's review. Consumer dispute rights commonly run around 120 days from the transaction or expected delivery date, so those months are not complete. In five minutes, with no statistics vocabulary, explain why the decline is not yet evidence and say exactly what you would put on the slide instead.

PracHub interview preparation framework ↗
Is this an official Aman interview guide?

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

PracHub interview research ↗
How difficult are the technical interviews?

The difficulty is generally considered moderate, but the focus is on practical application rather than theoretical trivia. Be prepared to explain the "why" behind your technical choices.

PracHub interview research ↗
How much time should I spend preparing for the use case assessment?

The use case is a significant part of the evaluation. Dedicate enough time to treat it as a real work project—focus on clean code, clear documentation, and a well-structured summary of your findings.

PracHub interview research ↗
What is the company culture like for a Data Scientist?

Aman values data-driven decision-making and collaborative problem-solving. You will be expected to work independently but also to communicate your findings effectively to non-technical partners.

PracHub interview research ↗
How long is the typical interview process?

The timeline varies, but from the first screen to the final decision, it usually spans a few weeks. Keep your communication with the recruiter prompt to stay on track.

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.