Professional Python Data Engineer Assessment

Q: What is this python-backend mock test?

This is a comprehensive python-backend mock test with 30 questions covering Architecture, Spark, Data Formats. It simulates real technical interviews with timed conditions and provides detailed explanations.

Q: How long does the test take?

The test has a time limit of 90 minutes. You can pause and resume, but we recommend completing it in one sitting.

Q: Will I get feedback on my answers?

Yes! After each question, you receive immediate feedback with detailed explanations. At the end, you get a comprehensive report showing your strengths and areas for improvement.

Q: Is this test suitable for FAANG interview preparation?

Absolutely! Our questions are curated by FAANG interviewers and cover the exact topics and difficulty levels you'll encounter in top tech company interviews.

Question 1

What is the primary difference between ETL and ELT architectures in modern data warehousing?

Answer

ETL transforms data before loading it into the warehouse; ELT loads raw data first and leverages the warehouse's compute power for transformation

Question 2

In Apache Spark, what is the difference between a 'Transformation' and an 'Action'?

Answer

Transformations are lazy (build an execution plan); Actions trigger the actual computation and return results

Question 3

Which file format is 'columnar' and highly optimized for analytical queries in big data ecosystems?

Answer

Apache Parquet

Question 4

What is 'Data Partitioning' in a distributed database or file system (like HDFS or S3)?

Answer

Dividing a large dataset into smaller, manageable chunks based on a key (e.g., date or region) to improve query performance

Question 5

In Apache Airflow, what is a 'DAG'?

Answer

Directed Acyclic Graph; a collection of all the tasks you want to run, organized in a way that reflects their relationships and dependencies

Question 6

What is the 'Lambda Architecture'?

Answer

A data-processing architecture designed to handle massive quantities of data by taking advantage of both batch and stream-processing methods

Question 7

What is 'Idempotency' in a data pipeline, and why is it critical?

Answer

The property where running a pipeline multiple times with the same input produces the same output without creating duplicates

Question 8

What is the difference between a 'Star Schema' and a 'Snowflake Schema' in data modeling?

Answer

Star has denormalized dimensions; Snowflake has normalized dimensions (where dimension tables link to other dimension tables)

Question 9

In Spark, what is 'Data Skew' and how can 'Salting' fix it?

Answer

Skew is an uneven distribution of data across partitions; Salting adds a random prefix to keys to distribute them more evenly during a shuffle

Question 10

What is 'CDC' (Change Data Capture)?

Answer

A set of software design patterns used to determine and track the data that has changed so that action can be taken using the changed data

Professional Python Data Engineer Assessment

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