All 75 questions
How do NumPy views and copies differ, and how can you check whether arrays share memory?
Asked in 2 of 281 interviews · last asked Jun 3 · Concept · Mid-level
Other ways it was asked
- “In NumPy, how does a view differ from a copy, and how can you tell which one you got after slicing?”
- “In NumPy, what's the difference between a view and a copy, and how do you prevent accidental data mutation when slicing?”
- “How would you check in code whether a sliced NumPy array shares memory with the original array?”
How would you troubleshoot and optimize a Python data pipeline that fails as data volume grows?
Asked in 2 of 281 interviews · last asked Sep 9 · Scenario · Senior
Other ways it was asked
- “If a Python script that processes terabytes of data suddenly starts failing during a huge data spike, how do you go about solving it?”
- “How would you troubleshoot and optimize an inherited Python ingestion service that handles 10,000 records fine but crashes or slows down at 10,000,000 records without rewriting it?”
What is NumPy, and why is a NumPy array generally faster than a Python list for numerical operations?
Asked in 2 of 281 interviews · last asked Oct 17 · Concept · Mid-level
Other ways it was asked
- “What is NumPy, and why is it preferred over regular Python lists for numerical computation?”
Why is Python used in machine learning?
Asked in 2 of 281 interviews · last asked Aug 14 · Concept · Junior
Other ways it was asked
- “Why is Python used in AI and data science?”
How would you use Python to process terabytes of data reliably?
Asked once · last asked Aug 12 · Scenario · Senior
Other ways it was asked
- “How would you optimize Python code that processes terabytes of data?”
What data do you pass to scikit-learn to train a model, and what does the training call return?
Asked once · last asked Sep 10 · Concept · Junior
How do you make a PySpark function available outside a particular notebook session?
Asked once · last asked Sep 15 · Tooling · Mid-level
Other ways it was asked
- “How do you make a PySpark function available for use in other notebooks or sessions?”
- “How do you make a reusable PySpark function available across Microsoft Fabric notebooks?”
How would you clean data using bulk SQL queries versus a Python script, and when would you choose each approach?
Asked once · last asked Mar 6 · Scenario · Mid-level
Can you describe a specific project where you used Python and machine learning frameworks to solve a real-world problem, including the problem, your approach, and the outcome?
Asked once · last asked Mar 27 · Behavioral · Mid-level
How do you connect a Python file to a MySQL database?
Asked once · last asked Apr 9 · Tooling · Junior
How do you implement idempotency and exactly-once behavior in your Python ETL when a delayed partition arrives and triggers a backfill?
Asked once · last asked Apr 25 · Scenario · Senior
When you validate incoming data in Python, what checks do you treat as hard failures versus quarantined bad records, and how do you route or report them?
Asked once · last asked Apr 25 · Scenario · Senior
In a Python batch ETL, how would you design pipeline retries so transient errors are retried safely but data quality failures don't cause endless reprocessing?
Asked once · last asked Apr 25 · Scenario · Senior
How do you structure your Python exceptions or error taxonomy so the orchestrator, for example Airflow, can distinguish retryable from non-retryable failures and alert appropriately?
Asked once · last asked Apr 25 · Tooling · Senior
In Python, how would you implement a reusable data quality framework with rules, severities, and metrics that works across multiple pipelines while still supporting dataset-specific checks?
Asked once · last asked Apr 25 · Design · Senior
How would you structure a scikit-learn pipeline that includes lag or rolling features from a timestamped series without leaking future information, given that a pipeline doesn't natively know about time order?
Asked once · last asked May 3 · Scenario · Senior
What attributes would you store during fit or fit_transform to support stateful behavior, and how would you ensure get_params() and set_params() still work for scikit-learn cloning?
Asked once · last asked May 3 · Concept · Senior
How would you write a Python script using pandas to read a CSV file of user data, filter rows where country is US, and write the filtered data to a new CSV file, explaining the main steps and functions?
Asked once · last asked May 18 · Write code · Junior
Other ways it was asked
- “In Python, how would you write a simple script using pandas to read a CSV file of user data, filter rows where the country is US, and write the filtered data to a new CSV file? Could you walk me through the main steps and functions you would use?”
Could you explain the difference between a Python list and a pandas Series or DataFrame? In a data engineering context, when would you prefer pandas over basic Python data structures?
Asked once · last asked May 18 · Concept · Junior
You receive a log file where each line has a user ID, timestamp, and action. How would you write a Python script using pandas to load the file, parse the timestamp into a datetime type, and compute the number of actions per user per day?
Asked once · last asked May 18 · Write code · Junior
In Python, what's the practical difference between a list, a tuple, and a NumPy array, and when would you choose each in an ML pipeline?
Asked once · last asked Jun 3 · Concept · Junior
What practical implications does NumPy operating in C have for performance and memory compared with Python lists?
Asked once · last asked Jun 3 · Concept · Mid-level
In Python, how would you make ML experiment results reproducible across runs, and what are common sources of nondeterminism even after setting random seeds?
Asked once · last asked Jun 3 · Scenario · Senior
What are the advantages of Alembic migrations?
Asked once · last asked Jun 24 · Concept · Mid-level
How do you sort an array using NumPy, and what is the syntax?
Asked once · last asked Jul 26 · Tooling · Junior
Show Python code for logistic regression and how you would use it to get a yes/no prediction.
Asked once · last asked Jul 26 · Write code · Junior
How would you use Python to find the best-selling product by total quantity sold?
Asked once · last asked Aug 3 · Write code · Junior
How would you separate calculation from presentation in a workflow that includes SPSS/Python code, data prep, outlier handling, multiple imputation, and automated reporting, and what are the benefits and drawbacks?
Asked once · last asked Aug 6 · Scenario · Mid-level
Can you write Python code for a linear regression algorithm, from importing the data through making predictions?
Asked once · last asked Aug 11 · Write code · Mid-level
Describe a failure or misleading result in a Python data workflow, and how you detected and corrected it.
Asked once · last asked Aug 12 · Behavioral · Mid-level
Which Python tools can you use to manage database migrations?
Asked once · last asked Aug 13 · Tooling · Mid-level
How would you implement a cosine similarity function using NumPy?
Asked once · last asked Aug 19 · Write code · Mid-level
How would you write Python code to read an Excel file, filter rows where the status column is active, and write the results to another Excel file?
Asked once · last asked Aug 22 · Write code · Mid-level
How are consultants balancing traditional actuarial tools with newer programming languages or automated data pipelines like Python when building client models?
Asked once · last asked Aug 28 · Concept · Mid-level
When would you use Python transformations instead of implementing the logic in SQL?
Asked once · last asked Aug 29 · Concept · Mid-level
How do you ensure data is accurate and reliable when preparing it for a model using SQL and Python?
Asked once · last asked Aug 31 · Scenario · Senior
What is the difference between Python and PySpark?
Asked once · last asked Aug 31 · Concept · Junior
How can Python connect to a SQL database?
Asked once · last asked Sep 3 · Concept · Mid-level
What is vectorization in Python, and when would you use it?
Asked once · last asked Sep 3 · Concept · Mid-level
How would you explain the structure and execution flow of a PyTorch neural network?
Asked once · last asked Sep 3 · Tooling · Mid-level
How would you write a Python function to find the highest salary in each department?
Asked once · last asked Sep 4 · Write code · Mid-level
Write Python code to filter rows where quantity is greater than 100, category starts with "t", and active is false.
Asked once · last asked Sep 4 · Write code · Mid-level
Other ways it was asked
- “Write Python code to filter rows where quantity is greater than 100, category starts with "t," and active is false.”
When pulling a database containing 50,000,000 rows from SQL Server into Python, how do you prevent memory error exceptions? Compare memory-safe techniques.
Asked once · last asked Sep 5 · Scenario · Senior
How does connection pooling work in Python applications connecting to SQL Server, and why is it useful for distributed application services?
Asked once · last asked Sep 5 · Concept · Senior
Other ways it was asked
- “How does Python connection pooling operate behind the scenes in systems like SQL Server, and why is it mandatory for distributed application services?”
How could you use SQL and Python in a banking risk role?
Asked once · last asked Sep 5 · Scenario · Junior
How would you structure a Python workflow to run daily with parameterized dates, log metrics, and remain idempotent after partial failure?
Asked once · last asked Sep 7 · Scenario · Senior
Other ways it was asked
- “Switching to automation, how would you structure a Python workflow to run daily parameterized dates, log metrics, and remain idempotent after partial failure?”
How do you identify outliers in Python?
Asked once · last asked Sep 9 · Scenario · Mid-level
Why do we need XCom instead of just using Python global variables in Airflow?
Asked once · last asked Sep 10 · Concept · Mid-level
Why can Python appear slow for OpenCV tasks, and where is the image-processing work actually executed?
Asked once · last asked Sep 11 · Concept · Senior
How do you implement binning in Python?
Asked once · last asked Sep 20 · Tooling · Junior
How would you choose between delivering a Jupyter notebook and a script that runs with credentials?
Asked once · last asked Sep 22 · Scenario · Mid-level
How would you develop a custom Python component for Airflow beyond DAG definitions, and handle errors and retries in that component?
Asked once · last asked Sep 23 · Tooling · Senior
Other ways it was asked
- “What Python component did you personally develop in Airflow beyond DAG definitions, what did it do, and how did you handle errors and retries?”
How would you automate the retraining process in Python, especially the workflow and scheduling mechanics?
Asked once · last asked Sep 24 · Scenario · Mid-level
How would you structure a Python benchmarking pipeline, including its inputs, outputs, and implementation?
Asked once · last asked Sep 29 · Tooling · Mid-level
How would you organize a Python script for migrating data to ClickHouse into modules or functions, and what systems would it interact with?
Asked once · last asked Oct 1 · Tooling · Mid-level
How would you use Python to process and analyze satellite imagery?
Asked once · last asked Oct 9 · Tooling · Mid-level
In Python, how would you estimate time-varying factor exposures using methods such as rolling or state-space regression, then test whether residual alpha is statistically significant out of sample?
Asked once · last asked Oct 10 · Scenario · Senior
In Python, how do you diagnose and mitigate multicollinearity so that time-varying betas and residual alpha remain stable?
Asked once · last asked Oct 10 · Scenario · Senior
In Python, how would you implement an as-of join that maps each trade decision timestamp to the latest available macro vintage by release time at scale across many series?
Asked once · last asked Oct 15 · Write code · Senior
How do you validate in Python that no decision row ever matched a macro release with release time after decision time, and how would you surface violations quickly on a large dataset?
Asked once · last asked Oct 15 · Write code · Senior
How would you structure a walk-forward in Python so feature engineering and standardization, for example z-score scaling, are fit only on the training window and then applied to the test window without leakage?
Asked once · last asked Oct 15 · Write code · Senior
What is broadcasting in NumPy?
Asked once · last asked Oct 17 · Concept · Mid-level
What is PyTorch, and what advantages does it provide for deep learning compared with using NumPy alone?
Asked once · last asked Oct 17 · Concept · Mid-level
How does PyTorch autograd calculate gradients during backpropagation?
Asked once · last asked Oct 17 · Concept · Mid-level
Other ways it was asked
- “What is autograd in PyTorch?”
- “Can you explain how PyTorch calculates gradients during backpropagation?”
How do you use pandas in Python?
Asked once · last asked Jan 31 · Tooling · Mid-level
What does Alembic do?
Asked once · last asked Feb 23 · Tooling · Junior
How can you detect speech using Python?
Asked once · last asked Jul 16 · Tooling · Junior
How does a Python speech-processing workflow capture input and produce output?
Asked once · last asked Jul 16 · Concept · Junior
How would you create a sparse matrix in Python?
Asked once · last asked Jul 20 · Write code · Mid-level
Which Python library has logistic regression?
Asked once · last asked Jul 26 · Concept · Junior
What is NumPy?
Asked once · last asked Aug 19 · Concept · Junior
How would you use a Python script to process data, format files, or change file configurations in a data pipeline?
Asked once · last asked Sep 9 · Tooling · Mid-level
How would you review a Python processing workflow to identify potential issues or areas for improvement?
Asked once · last asked Sep 20 · Scenario · Mid-level
Other ways it was asked
- “How would you review a Python code process to identify potential issues or areas for improvement?”
Can you explain the concepts of shape and dtype in NumPy?
Asked once · last asked Oct 17 · Concept · Junior
What is a PyTorch tensor?
Asked once · last asked Oct 17 · Concept · Junior
More Python interview questions
- All Python interview questions
- Python Basics Interview Questions
- Python Data Structures and Coding Interview Questions
- Python Functions, Decorators and Generators Interview Questions
- Python Files, Exceptions and Modules Interview Questions
- Python APIs, Web Frameworks and Deployment Interview Questions
How this list is made
Every question here was asked by a real interviewer in a real job interview that a candidate ran MeetAssist in. After the call, the interviewer's questions are pulled from the transcript. Practice sessions, tests, exams and anything that was not a job interview are dropped.
Questions are rewritten so they make sense on their own: names of people, employers and clients are removed, and speech-to-text mistakes are fixed. Small talk, logistics and questions about one candidate's own résumé are left out. Rephrasings of the same question are merged, and the count is the number of different interviews it came up in.
The interviews come from candidates who use MeetAssist, so they lean towards software, data and AI roles: the shares describe these interviews, not every Python interview. Answers to the most asked questions are written and checked by an editor; a "common mistake" is shown only when reviews of real answers in these interviews show it, with the count.
281 interviews, 199 candidates, Nov 2025 to Oct 2026. Updated every month with new interviews.
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