The best AI interview assistant for data science interviews depends on the round: SQL and Python need a tool that grades code, statistics and A/B testing need one that pushes back on your reasoning, and product and metric cases need spoken practice with follow-ups. Our overall pick is CoPilot Interview, which builds spoken mock interviews from your résumé and the job description and scores each answer out of 10, free for 15 minutes a day; StrataScratch and Interview Query are the strongest data-specific alternatives.
Below we match seven tools to the data science rounds each fits best, using each vendor's own site, checked October 2026. This page belongs to our state of AI interview assistants 2026 library. If you already have a tool and want a round-by-round playbook, read our guide to using an assistant in each data science round.
The 7 best AI tools for data science interviews at a glance
Disclosure: we make CoPilot Interview. It is listed first and marked Best choice where we think that's accurate; its limits are in its review. "Not stated" or "not verified" means we couldn't confirm it on the vendor's own site.
| Tool | Best-fit rounds | How it practices | Feedback | Free option | Paid from (checked October 2026) |
|---|---|---|---|---|---|
| CoPilot Interview | Best choice for behavioral, product and metric, and spoken technical rounds | Questions read aloud from your résumé and job description; you answer out loud | Score out of 10, what to fix and a model answer, then a report card | Best choice: 15 minutes every day, no card or signup; browser mock with SQL and data science tracks | $14.99/mo Standard (sale; regular $19.99) |
| StrataScratch | SQL, Python and ML concepts | AI mock interviews for Data Scientist, ML Engineer and AI Engineer roles, by company and difficulty | Scores code quality, correctness and communication; AI Evaluator for concept answers | Free start, no credit card | $139 a year or $289 lifetime |
| Interview Query | Analytics, product and ML technical rounds | AI Interviewer with timed, multi-step questions and follow-ups; you write SQL or Python | Instant feedback | Not verified | Not verified |
| Aced (formerly Exponent) | SQL and product-style rounds; data science course | Voice AI mock interviews; SQL interviews include a code editor | Scored rubric | Basic: sample lessons, 5 peer mocks a month | Expert $99/mo, or $20/mo billed annually |
| interviewing.io | ML rounds with a senior engineer | Free AI Interviewer for coding and system design; human ML mocks | Feedback from the engineer after the session | AI Interviewer is free | Human mocks from $179 a session |
| ChatGPT | Statistics drills, concept review, take-home narrative | Whatever you prompt; voice and image uploads on the free plan, with limits | Only what you ask for | Free plan | Plus $20/mo |
| Claude | Long critiques of case answers and write-ups | Whatever you prompt; voice mode on every plan, in beta | Only what you ask for | Free plan | Pro $20/mo, or $17/mo billed annually |
We couldn't load Interview Query's pricing page in October 2026, so check it there before you buy. For the general field, see our 15-tool comparison.
Which data science rounds can an AI interview assistant help with?
An AI interview assistant is software that uses speech-to-text and a large language model to run practice interviews, suggest structured answers and give feedback. Data science loops mix very different rounds, and no single tool is best at all of them. This is how we'd split the work.
| Round | What's tested | Best-fit practice |
|---|---|---|
| SQL | Joins, aggregation, window functions, edge cases such as nulls and duplicates | A graded code editor (StrataScratch, Aced), then explain your query out loud in a CoPilot Interview mock |
| Python and pandas | Data wrangling, simple algorithms, clean code | StrataScratch or Interview Query for code; CoPilot Interview's coding mode to check your solution in your chosen language |
| Statistics and A/B testing | Hypothesis tests, power and sample size, experiment pitfalls, interpreting results | Spoken scenario questions with follow-ups; a chatbot for concept drills you verify |
| ML concepts | Bias and variance, regularization, evaluation metrics, leakage | StrataScratch ML mocks; CoPilot Interview mocks with a technical mix |
| Product and metric cases | Defining success metrics, diagnosing a drop, trade-offs | Spoken mocks: CoPilot Interview, Interview Query |
| Take-home review | A clear narrative, sound methods, honest limits | Rehearse presenting your finished work out loud; see the take-home tips below |
| Behavioral | Impact, stakeholder work, using data to decide | CoPilot Interview mocks built from your résumé |
For question banks by round, see our 30 data scientist interview questions and the SQL patterns that repeat.
How each data science interview tool compares
1. CoPilot Interview: Best choice for spoken, job-specific practice
CoPilot Interview is a desktop app for Windows 10+ and macOS 12+. In Mock Interview, you add your résumé and the job description and choose the level, 3, 5 or 8 questions, the mix (behavioral, technical, system design, coding), your coding language and an optional focus such as "A/B testing" or "churn metrics". It reads each question aloud, listens to your spoken answer and scores it out of 10 with what worked, what to fix and a model answer, then a report card. Coding questions never auto-submit, so you can think before you speak.
Data science interviews reward people who can explain a messy analysis simply, and that's the skill a spoken mock trains. The browser AI mock interview adds 113 real questions across 9 tracks, including data science and ML and SQL, with nothing to install.
- Strengths: a free plan of 15 minutes every day across all four modes; questions drawn from the job you want; one tool for the behavioral and case rounds that often decide data science offers.
- Limits: it doesn't run your SQL against a database or grade a notebook; no human coach or human feedback; the full app is desktop only (Windows and macOS), with the Android companion a beta outside Google Play; free sessions stop at 15 minutes.
- Price: Free $0; Standard $14.99/mo on sale (regular $19.99) with 60-minute sessions, up to 100 minutes a day and no gap between sessions; Pro $29.99/mo; Pro+ $49.99/mo. See pricing.
Our data science interview help page covers how CoPilot Interview handles ML, SQL and statistics questions.
2. StrataScratch: best for SQL, Python and ML mocks with code
Per its homepage, StrataScratch runs "AI-powered mock interviews for Data Scientist, ML Engineer, and AI Engineer roles". You pick a role, company and difficulty, and scoring covers code quality, correctness and communication, with a review of your reasoning. Its AI Evaluator scores concept answers on completeness, accuracy, depth and structure. You can start free with no credit card. Its pricing page listed $139 a year and $289 lifetime in October 2026; check the monthly option there.
Strengths: the most data-specific AI mock we could verify, with real code. Limits: its AI mocks are built around code and concept questions, so pair it with a speaking tool for product cases and behavioral rounds.
3. Interview Query: best for analytics and product-style technical rounds
Interview Query describes its AI Interviewer as interactive mock interviews for data science, analytics, ML and technical product roles, with timed, multi-step questions and follow-ups, where you write queries or code and get instant feedback. It also has a large bank of company interview guides.
Limits: we couldn't load its pricing page in October 2026, so we don't quote a price; confirm plans and what the free tier includes before you pay.
4. Aced (formerly Exponent): best course plus voice mocks
Aced's AI mock interviews connect you by audio to an AI interviewer; SQL is one of the listed types and includes a code editor, and you get a rubric score on communication, problem-solving and structured thinking. Aced also sells a data science course. AI mock interviews and AI feedback are listed on the Expert plan at $99/mo, or $20/mo billed annually, as of October 2026; memberships are refundable within 5 days.
Limits: data science and ML aren't listed as an AI mock type on that page, so the AI side is strongest for SQL and product-style rounds.
5. interviewing.io: best human check for ML rounds
interviewing.io offers anonymous mocks with senior engineers, and machine learning algorithms and ML system design are among its subjects, from $179 a session as of October 2026. Its free AI Interviewer covers coding and system design, useful if your data science loop includes a general coding round.
Limits: no AI mock for statistics or product cases, and human sessions are priced for the final week, not daily practice.
6. ChatGPT: best free statistics drill partner
ChatGPT is good at generating scenario questions and explaining concepts at the level you ask for. OpenAI's help center says the free plan includes limited voice and image uploads; Plus is $20/mo as of October 2026. Limits: it can be confidently wrong on a formula, so treat every number as a claim to check.
7. Claude: best for critiquing written cases and take-home narratives
Claude handles long documents well, which suits critiquing a case write-up or the story you'll tell about a finished analysis. Voice mode is on every plan, in beta, and per Claude's pricing page Pro is $20/mo or $17/mo billed annually as of October 2026. Limits: like any chatbot, it won't score you against an interview rubric unless you give it one.
Practice it: a week of data science mocks
- Monday, SQL. Solve three graded SQL problems, then explain one out loud in under two minutes: the tables, the join, the edge case.
- Tuesday, statistics. Answer three A/B testing scenarios aloud before checking any explanation.
- Wednesday, mock. Run a 5-question CoPilot Interview Mock Interview from the job description with a technical and behavioral mix. Note the two lowest scores.
- Thursday, product case. Practice one metric definition and one "the metric dropped 10%" diagnosis, out loud, in 10 minutes each.
- Friday, redo. Re-answer your two weakest questions from Wednesday in your own words, and compare the report cards.
An A/B testing question we wrote, with an outline: "Your test shows a 2% lift in conversion with p = 0.04 after three days. Do you ship?" A strong answer checks whether three days matches the planned duration and sample size, whether weekly patterns or a novelty effect could explain the lift, whether several metrics were tested (raising the chance of a false positive), and whether guardrail metrics such as refunds moved. It ends with a decision and what you'd monitor after launch.
If you use any tool in a live round, follow the rules of the employer or platform you're interviewing with — many people use it only to practice, which works on the free plan. Take timed SQL tests and online assessments yourself.
Which tool should you choose for your data role?
- Product data scientist or analyst: CoPilot Interview for spoken metric cases and behavioral rounds, plus Interview Query for analytics questions. Analysts can also read our data analyst guide.
- SQL-heavy loops: StrataScratch or Aced for graded queries, then spoken explanations in CoPilot Interview.
- ML-leaning data scientist: StrataScratch's ML mocks and one human ML mock near the end. Machine learning engineers should read our AI practice guide for machine learning engineers, since MLE loops add ML system design and production questions.
- On a zero budget: CoPilot Interview's free plan, StrataScratch's free start and a free chatbot.
Start with CoPilot Interview's free AI interview assistant for spoken reps. If your loop also has a general coding round, see our picks for the best AI tools for coding interviews.
Rehearse data science answers out loud, free
Build a mock interview from your résumé and the job description, answer out loud, and get each answer scored out of 10 with what to fix and a model answer. 15 free minutes every day on Windows or macOS, no card or signup.
Download CoPilot Interview freeFAQ
What is the best AI interview assistant for data science interviews?
Our pick is CoPilot Interview for spoken, job-specific practice, and we make it, so weigh that: Mock Interview builds questions from your résumé and the job description and scores each spoken answer out of 10, free for 15 minutes a day. For SQL and ML mocks with code, StrataScratch's AI mock interviews are the strongest data-specific alternative we could verify in October 2026; Interview Query's AI Interviewer covers analytics and product-style rounds.
Which AI tool is best for SQL interview practice?
Use a tool with a code editor that grades your query. As of October 2026, StrataScratch's AI mock interviews score code quality, correctness and communication, and Aced's AI mock interviews include a SQL type with a code editor. CoPilot Interview's browser mock interview has a SQL track if you want to practice explaining queries out loud.
Can AI help with statistics and A/B testing interview questions?
Yes, as a drill partner. Ask it for scenario questions (a test that ran three days, a metric that moved the wrong way) and answer out loud before reading its view. Check every formula and number yourself, because chatbots can state a wrong power calculation or p-value interpretation fluently.
Is it OK to use AI on a data science take-home assignment?
Only if the employer allows it, and many take-home instructions say whether it is. Read the instructions, ask the recruiter if they are silent, and never paste a company's confidential data into a chatbot. Using AI to rehearse explaining your finished analysis is a safer use.
Is there a free AI mock interview for data science?
Yes. CoPilot Interview's free plan includes Mock Interview for 15 minutes every day, and its browser mock interview has data science and ML and SQL tracks with nothing to install. StrataScratch lets you start free with no credit card, and ChatGPT and Claude have free plans you can prompt to act as an interviewer.
Can I use AI during a live data science interview?
Only if the employer allows it. Follow the rules of the employer or platform you're interviewing with — many people use it only to practice, which works on the free plan. Never use one during an online assessment or a timed SQL test; take it yourself.