Банк вопросов из реальных собеседований

What is a decorator, why is it needed, and why is the code inside the generator executed when iterated rather than when created?

How to write a decorator to log a call, why is functools.wraps needed, and how to lazily import a module inside a wrapper?

What are the tasks in the industrial ML MLflow, reproducible piplins, PySpark and feature storage?

What are the tasks in the industrial ML MLflow, reproducible piplins, PySpark and feature storage?

What are the tasks in the industrial ML MLflow, reproducible piplins, PySpark and feature storage?

What happens inside the Python for-loop, how does an iterator differ from a generator, and why is StopIteration needed?

How are arguments passed to functions in Python? What happens if a function mutates a list argument versus reassigning an immutable value?

How to compare forecast models if LLM-extractor can know future facts from pretraining?

The business wants to know whether the user will return and whether to give him a discount. How to formulate ML-task, target and signs?

In a casino product, the sales team needs to understand as early as possible whether the new player will become a VIP in terms of deposits and turnover. How to formulate a ML-task, target, forecast horizon and business action?

The interview shows a class that reads the file, stores the DataFrame and does the processing. What problems do you look for in this code?

Explain how the Python dict works and how the regular list differs from the NumPy array.

What neural network approaches can be used in RecSys and where do they stand in the pipeline?

The player has just entered the casino product. What signs can be collected in the first days to distinguish a potential VIP from an ordinary player?

You have a linear-regression baseline for LTV. When is gradient boosting likely to help, and how would you decide whether to move to it?

How would you design a backend pipeline that ingests market and alternative data, produces ML signals, applies risk controls, and hands decisions to execution?

You can run four Python applications as systemd services on one VM or as four containers. What practical guarantees do containers add?

How are matrix equation, least squares, gradient descent and L1/L2 regularization related?

Marketing wants to know how much it can pay for acquisition without losing money. Why might MSE be insufficient for LTV prediction, and what metric or objective would you add?

What exactly should be counted in metrics: timestamps, operation duration, or error values themselves?

For a new player, you need to understand when you can already trust the VIP status forecast. How to assess at what day in a client’s life the model gives a sufficiently useful signal?

For a new player, you need to understand when you can already trust the VIP status forecast. How to assess at what day in a client’s life the model gives a sufficiently useful signal?

You review code that loops over texts, calls an embedding model one by one and appends outputs to a NumPy array. What would you improve?

What does it mean to take an ML model from training to production, and which pieces should an ML engineer be able to own?