New Relic · Data Scientist
Updated · 2026-09-22

New Relic Data Scientist
Interview Questions & Guide 2026

THE 60-SECOND BRIEF

As a Data Scientist at New Relic, you play a pivotal role in transforming data into actionable insights that drive product innovation and enhance user experience. This position is essential for leveraging complex data sets to inform strategic decisions, optimize platform performance, and deliver exceptional value to clients. Your contributions will directly impact New Relic's mission of helping organizations monitor and manage their software performance, making this role both critical and rewarding.

Learn the economics of the product category before the loop. Marketplaces, subscription products and ad-supported products turn on different core quantities (match rate and liquidity, retention and churn, fill rate and yield) and fail in different characteristic ways.

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

Size an experiment before anyone launches itPick a randomisation unit that respects interferenceSeparate novelty effects from durable behaviour change

32 min read

Practice 17 Data Scientist prompts
4Candidate experiences ↗Read their reports
17Practice promptsAcross five skill areas
3With worked solutionsIncluded in the practice prompts

As a Data Scientist at New Relic, you play a pivotal role in transforming data into actionable insights that drive product innovation and enhance user experience. This position is essential for leveraging complex data sets to inform strategic decisions, optimize platform performance, and deliver exceptional value to clients. Your contributions will directly impact New Relic's mission of helping organizations monitor and manage their software performance, making this role both critical and rewarding.

The work of a Data Scientist at New Relic is characterized by its scale and complexity. You will engage with vast amounts of data across various products and teams, using advanced analytical techniques to identify trends, build predictive models, and guide product improvements. This role is not just about crunching numbers; it's about utilizing data to influence product direction and customer engagement, making it a strategic function that is integral to the company’s success.

Expect to collaborate closely with engineering, product management, and operations teams. You will work on challenging problems, such as optimizing user experiences, improving system reliability, and enhancing product features based on data-driven insights. The dynamic nature of this role ensures that your work will always be at the forefront of technology and innovation.

01

Initial Screening Call

reported

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
PracHub interview research ↗
02

Multiple Rounds of Interviews

reported

Rounds outside the standard loop often open with something deliberately under-specified: a loose business problem, an open question about a product area, a dataset described in one sentence. The common failure is surveying, listing six plausible approaches and committing to none of them. The thing that separates a strong answer is scoping out loud. State what you are treating as the goal, name the metric you would move, say what you are choosing not to do and why, then take one path through to an actual answer. An interviewer can follow you down a narrow path. Nobody can grade a menu.

What to demonstrate

  • Whether you turn an ambiguous prompt into a stated question with a measurable outcome before doing any work
  • The judgement visible in what you cut, and whether you say why you cut it rather than silently dropping it
  • Whether you land on a concrete recommendation with its caveat attached, rather than an unranked set of options

How to prepare

  • Take three vague prompts, such as 'is this feature working', 'why did retention drop', and 'should we expand into a new segment'. For each, write one sentence of goal, one primary metric with its window, and two things you are explicitly not doing.
  • Practise giving the recommendation first and the reasoning second, in five minutes. Loosely defined rounds are usually time-boxed, and an answer that arrives last often does not arrive.
  • Keep a running assumption list as you talk, on paper or in the shared doc, so the interviewer can challenge one assumption instead of your whole answer.
PracHub interview research ↗

4 candidate reports. Individual accounts describe a particular role and hiring cycle.

Backend Engineer

New Relic Backend Engineer Interview Experience — String Compression, Longest Increasing Path, and a Kafka Trace-Grouping Design

Onsite

Question 1: Implement a method that does basic string compression by counting consecutive repeated characters. If the compressed string is not shorter than the original string, return the original string. Discuss time complexity and space complexity Discuss edge cases Discuss code optimization Question 2: Longest Increasing Path in a Matrix. You can only move in four directions (up, down, left, r…

Read full experience
Software Engineer

New Relic Software Engineer Interview Experience: good rounds followed by silence

Technical ScreenOutcome: ghosted

The early part moved quickly. I had technical rounds that went well in a single day, then a hiring-manager conversation a few days later. That conversation felt positive, and communication during it was easy and on track. What threw me off was everything afterward. HR went quiet, and when I messaged, I got nothing back. After about a week of silence, I wanted feedback, even negative feedback, bec…

Read full experience
Software Engineer

New Relic Software Engineer interview experience: SDE-2 Codility DSA

Technical ScreenOutcome: rejected

I interviewed for an SDE-2 track and was rejected after the first technical round. It was a DSA-focused coding session on Codility, centered on data structures and algorithms. The interviewer gave a brief introduction and moved straight to the coding questions. The prompts used real-life scenarios rather than only abstract problems. I did not move past that initial technical checkpoint, and it fe…

Read full experience
Software Engineer

Software Engineer interview at New Relic: delayed Portland process

Outcome: rejected

After the recruiter call, I waited almost two weeks before the hiring manager scheduled the Portland interview. On that call, the manager seemed disengaged and did little to build momentum, so the conversation felt flat and uninterested in my experience. Another couple of weeks passed with no update. The recruiter eventually said the search had narrowed and they were pausing candidates, followed…

Read full experience

PracHub editorial advice for the preparation topics above.

01

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.

02

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.

03

Building features from data that postdates the prediction time

Check every feature against the timestamp at which the model would actually score, and drop anything computed from a window that includes or follows the label event. For a forecasting use case, split train and test by time rather than at random, and split by entity when the same entity recurs.

04

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.

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

14 technical prompts3 include a worked solution

How would you implement a decision tree from scratch?

medium
machine learning and modelling

How would you implement a decision tree from scratch?

Approach
  1. Frame the prediction: the label, the moment of prediction, and the action it triggers.
  2. Check what information would not exist at prediction time, and exclude it.
  3. Say how the offline result would be validated online before it is trusted.
Follow-up
  • Where could label leakage enter this setup?
  • How would you choose the decision threshold, and who owns that choice?

Sessionise an event stream with gap and midnight rules

hard
sessionisationvectorisationevent streams

Sessionise a raw event stream. Input: a DataFrame with visitor_id, user_id (often NULL), occurred_at_utc and event_name, unsorted, up to 5 million rows. A session breaks when the gap from that visitor's previous event exceeds 30 minutes, and is force-closed at UTC midnight so no session spans two calendar dates. A gap of exactly 30 minutes does not break. Emit one row per session with session_id, visitor_id, the user_id as of the last event in the session, started_at_utc, ended_at_utc, session_date, duration_seconds and event_count. Vectorise; do not loop per visitor.

Approach
  1. Sort by ['visitor_id', 'occurred_at_utc', 'event_id'] once, then express the whole problem as one boolean vector: a row starts a new session when the visitor changed, or the gap exceeds 30 minutes, or the UTC date differs from the previous row's UTC date. Cumsum that vector and you have the session key.
  2. Get the comparison direction right on the gap: the rule is strictly greater than 1800 seconds, so an event at exactly 1800 seconds continues the session. Write it as gap > pd.Timedelta(minutes=30), and make the tie a test case rather than an assumption.
  3. Derive the midnight break from the date change, not from inserting synthetic boundary rows. A date change implies a break even when the gap is two seconds, which is precisely the force-close rule and is why the two conditions are ORed rather than one subsuming the other.
  4. Aggregate with a single groupby on the session key: min and max of occurred_at_utc, size for event_count, and last for user_id, which is correct because the frame is already sorted so 'last' is the final event in the session. That is the identity-as-of-session-end rule.
  5. Compute duration_seconds as (max - min).dt.total_seconds(), which makes a single-event session 0 seconds. Say so explicitly, because a downstream mean session duration is sensitive to whether single-event sessions are 0 or excluded.
Follow-up
  • Sessions are used as the denominator of a conversion rate. How does moving the inactivity gap from 30 to 45 minutes move that rate, and in which direction?
  • A visitor's clock is 40 minutes ahead, so their events arrive with future occurred_at values. What does your sessioniser do, and what would you rather it did?
  • The same person signs up mid-session on mobile and continues on desktop. How many sessions and how many users does your output show, and is that the right answer?

Rebuild per-visitor ordering without groupby convenience methods

easyWorked solution
pandasvectorisationwindow logic

You have a DataFrame of 2 million fct_event rows with visitor_id, occurred_at_utc and event_id, unsorted and containing duplicate timestamps within a visitor. Produce three new columns: event_rank, the 1-based position of the event within its visitor ordered by occurred_at_utc; seconds_since_prev, the gap to that visitor's previous event, NULL for the first; and is_first_for_visitor. You may use sort_values, shift, cumsum, numpy and boolean masking. You may not use groupby.transform, groupby.apply, groupby.cumcount, groupby.rank or merge_asof. Break timestamp ties on event_id.

Approach
  1. Sort once by ['visitor_id', 'occurred_at_utc', 'event_id'] and reset the index. The whole exercise reduces to row arithmetic on a sorted frame, and the tiebreak on event_id is what makes the result reproducible across runs.
  2. Mark visitor boundaries with is_first = df['visitor_id'].ne(df['visitor_id'].shift()). This is the single fact every other column derives from.
  3. Compute seconds_since_prev as the diff of the timestamp column, then overwrite it with NaT/NaN wherever is_first is True. The shift crosses the boundary between visitors and will otherwise hand the first row of each visitor the last event of the previous one.
  4. Build event_rank from a running counter that resets at boundaries: take a global cumulative position (np.arange(len(df))) and subtract, per row, the global position at which that visitor started. Get the start position by forward-filling the positions where is_first is True, which is a cumsum-free reset and is O(n).
  5. Verify against the forbidden method once, as a test rather than as the implementation, and confirm the two agree on every row.
Worked solution 20 min
  1. Sort on the three-key tuple and reset_index(drop=True).
  2. Compute is_first via .ne(.shift()), which is True for row 0 because the shifted value is NaN.
  3. pos = np.arange(len(df)); start = pd.Series(np.where(is_first, pos, np.nan)).ffill(); event_rank = (pos - start + 1).astype(int).
  4. gap = df['occurred_at_utc'].diff().dt.total_seconds(); gap[is_first] = np.nan.
  5. Assert event_rank equals df.groupby('visitor_id').cumcount() + 1 on the sorted frame.
EXPECTED RESULTThree columns on the sorted frame: event_rank starting at 1 for every visitor and increasing by 1 with no gaps, seconds_since_prev null exactly where is_first_for_visitor is True, and is_first_for_visitor summing to df['visitor_id'].nunique().
Follow-up
  • The frame does not fit in memory. How does your approach change if you can only process one visitor-partitioned chunk at a time?
  • occurred_at_utc is client-supplied and sometimes runs backwards within a visitor. Does your seconds_since_prev go negative, and should it?
  • How would you extend this to reset the counter at every change of surface as well as visitor?

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 ↗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 ↗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.

Work that nobody used is a common and unflattering pattern in data careers, and interviewers probe for it. Have a story about an analysis that changed a decision, and be specific about how you got it in front of the person who could act. Also have one about work that went nowhere, with your reading of why.

What does leadership mean to you in the context of data science?

medium
behavioural and stakeholder questions

What does leadership mean to you in the context of data science?

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. 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?

Handle a request for numbers supporting a decision already made

hard
integrityframingstakeholder

A senior leader has already decided to sunset a plan tier and asks you for the analysis showing it is the right call. Accounts on that tier carry 6% of MRR at constant FX and have the highest licensed-seat utilisation in the book. The leader's support matters to your next review cycle, and the decision is being presented in four days. Deliver what you produce, what you decline to produce, and the exact sentence you will say in the meeting where the number appears on a slide.

Approach
  1. Recognise what is being probed: whether you can find the legitimate request inside an illegitimate framing instead of either complying or refusing on principle. The generic answer promises to push back; the strong one produces something genuinely useful and states its limits in the room, without ambushing anybody.
  2. Separate the decision from the justification. Sunsetting the tier may be correct for reasons the data does not hold, such as support cost, roadmap surface area or sales motion. What you decline is a one-sided document. What you produce is the case read both ways, which also happens to be more useful to the leader.
  3. Build the symmetric analysis: MRR at risk at constant FX, the share of affected accounts with a plausible migration path given seats_licensed and billing_term, the recovery rate assumed for that migration and where it came from, and the downside case in which high-utilisation accounts treat the sunset as a reason to re-evaluate the vendor entirely.
  4. Surface the inconvenient fact privately and early. The highest seat utilisation in the book is a retention signal, and the leader should hold it before the room does, so they can incorporate it rather than be caught by it.
  5. Agree the meeting sentence in advance with the leader, so that nobody is surprised. Something to the effect that the tier is 6% of MRR and its accounts are the most heavily used in the book, and that the case for sunsetting rests on cost and focus rather than on revenue. That is true, it supports the decision on its real grounds, and it stops the deck claiming the numbers endorse it.
  6. Decide your own line before you need it: what you will not put your name to, and that the route if asked anyway is your own manager rather than a confrontation in the meeting.
Follow-up
  • The deck circulates with your analysis included and the downside case removed. What do you do, and by when?
  • What changes if the honest analysis says the sunset is clearly the wrong call?
  • How do you write the same memo when the leader is your skip-level and the meeting is tomorrow?

Explain a wide interval to a non-technical executive

medium
communicationuncertaintypricing

A pricing change is under consideration. Your best estimate of its effect on trial-to-paid conversion is a 1.8pp drop, with a 95% interval from a 4.6pp drop to a 1.0pp rise, read from a geo holdout rather than a randomised test. An executive preparing a board slide asks you for 'the number'. You have ninety seconds and one slide, and the words confidence interval, p-value and significance are not usable with this audience. Deliver the slide headline, the single supporting line, and what you say aloud.

Approach
  1. Recognise what is being probed: whether you can carry uncertainty into a decision instead of either hiding it or hiding behind it. The generic answer promises to explain the interval in plain English; the strong one replaces the question 'what is the number' with 'across this range, where does the decision change'.
  2. Find the threshold before you draft anything. Ask what the pricing case assumes, then compute the conversion drop at which the higher price stops adding revenue: price uplift on the conversions kept against the revenue lost from conversions forgone. That single figure is what makes the range legible.
  3. Restate the estimate and both bounds in the unit the audience already reasons in. Convert percentage points into monthly first-paid conversions at current trial volume, then into mrr_cents_constant_fx, so the slide reads as money per month rather than as statistics.
  4. Place the range against the break-even and say which part of it sits on each side. If most of the range clears the threshold, that is a recommendation to proceed with a monitoring plan; if the range straddles it, that is a recommendation to narrow the range first.
  5. Name what would narrow it and what that costs in weeks, then give one recommendation with an explicit condition for revisiting it. Uncertainty stated without a next step is read as indecision and the midpoint gets used anyway.
Follow-up
  • The executive says to give the midpoint and they will manage the risk. What do you do?
  • How does the slide change if the interval were a 4.6pp to 0.2pp drop, with no positive outcomes in range?
  • Why is a geo holdout the credible read here rather than the attributed channel numbers you already have?
  • 01

    What does leadership mean to you in the context of data science?

  • 02

    A senior leader has already decided to sunset a plan tier and asks you for the analysis showing it is the right call. Accounts on that tier carry 6% of MRR at constant FX and have the highest licensed-seat utilisation in the book. The leader's support matters to your next review cycle, and the decision is being presented in four days. Deliver what you produce, what you decline to produce, and the exact sentence you will say in the meeting where the number appears on a slide.

  • 03

    A pricing change is under consideration. Your best estimate of its effect on trial-to-paid conversion is a 1.8pp drop, with a 95% interval from a 4.6pp drop to a 1.0pp rise, read from a geo holdout rather than a randomised test. An executive preparing a board slide asks you for 'the number'. You have ninety seconds and one slide, and the words confidence interval, p-value and significance are not usable with this audience. Deliver the slide headline, the single supporting line, and what you say aloud.

PracHub interview preparation framework ↗
Is this an official New Relic interview guide?

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

PracHub interview research ↗
What is the typical interview difficulty for the Data Scientist role?

The interview process for this role is rigorous, focusing on both technical expertise and behavioral competencies. Candidates should prepare for challenging questions that require a deep understanding of data science principles.

PracHub interview research ↗
How much preparation time is recommended?

Candidates typically benefit from at least 2-4 weeks of focused preparation, dedicating time to brush up on technical skills and to practice behavioral questions.

PracHub interview research ↗
What differentiates successful candidates?

Successful candidates demonstrate a strong technical foundation, effective communication skills, and the ability to apply data insights to real-world business challenges. They also show alignment with New Relic's culture of innovation and collaboration.

PracHub interview research ↗
What is the typical timeline from initial screen to offer?

The interview process can vary, but candidates generally receive feedback within 2-3 weeks after the final interview. The overall timeline from initial screening to an offer can take 4-6 weeks.

PracHub interview research ↗
Sources & methodology 3 sources ↗

Official role evidence, timestamped platform data and clearly labeled preparation advice.