Real interview questions from top companies for Data engineer. Includes theoretical concepts and coding problems.
What is the primary function of a data engineer?
The primary function of a data engineer is to design, build, and maintain large-scale data systems, including data pipelines, architectures, and infrastructure.
What is the difference between a data engineer and a data scientist?
A data engineer is responsible for designing and building the infrastructure to store and process data, while a data scientist is responsible for analyzing and interpreting the data to gain insights and make decisions.
What is Apache Spark and how is it used in data engineering?
Apache Spark is an open-source data processing engine that is used for large-scale data processing, machine learning, and data analytics. It is used in data engineering to build data pipelines, process data in real-time, and perform batch processing.
What is the purpose of data warehousing in data engineering?
The purpose of data warehousing is to provide a centralized repository for storing and managing data from various sources, making it easier to access and analyze the data for business intelligence and decision-making.
What is the difference between a relational database and a NoSQL database?
A relational database uses a fixed schema and is optimized for transactional data, while a NoSQL database uses a flexible schema and is optimized for large-scale, distributed data storage and retrieval.
What is data governance and why is it important in data engineering?
Data governance refers to the policies, procedures, and standards for managing data across an organization. It is important in data engineering because it ensures that data is accurate, consistent, and secure, and that it is used in compliance with regulatory requirements.
What is the purpose of data quality in data engineering?
The purpose of data quality is to ensure that data is accurate, complete, and consistent, and that it meets the requirements of the business. Data quality is important in data engineering because it ensures that data is reliable and trustworthy, and that it can be used to make informed decisions.
What is the difference between batch processing and real-time processing in data engineering?
Batch processing refers to the processing of data in batches, where data is collected and processed in large chunks. Real-time processing refers to the processing of data as it is generated, in real-time. Batch processing is typically used for historical data analysis, while real-time processing is used for applications that require immediate insights and decision-making.
What is the purpose of data architecture in data engineering?
The purpose of data architecture is to design and implement a comprehensive data management strategy that meets the needs of the business. Data architecture includes the design of data models, data warehouses, data lakes, and data pipelines, as well as the selection of data storage and processing technologies.
What is the difference between a data lake and a data warehouse?
A data lake is a centralized repository that stores raw, unprocessed data in its native format, while a data warehouse is a repository that stores processed and transformed data in a structured format. Data lakes are used for big data analytics and data science, while data warehouses are used for business intelligence and reporting.
What is the purpose of data security in data engineering?
The purpose of data security is to protect data from unauthorized access, theft, and corruption. Data security includes the implementation of access controls, encryption, and authentication mechanisms to ensure that data is secure and compliant with regulatory requirements.
What is the difference between a data engineer and a DevOps engineer?
A data engineer is responsible for designing and building data systems, while a DevOps engineer is responsible for ensuring the smooth operation of software systems. While there is some overlap between the two roles, data engineers tend to focus on data management and processing, while DevOps engineers focus on software deployment and operations.
What is the purpose of data monitoring in data engineering?
The purpose of data monitoring is to track the performance and health of data systems, including data pipelines, data warehouses, and data lakes. Data monitoring includes the use of metrics, logs, and alerts to detect issues and ensure that data systems are operating as expected.
Write a Python function to find the maximum value in a list of integers
deffind_max_value(lst): returnmax(lst)
Write a Java function to reverse a string
public String reverseString(String str) {
StringBuildersb=newStringBuilder(str);
return sb.reverse().toString();
}
Write a Python function to find the first duplicate in a list of integers
deffind_first_duplicate(lst): seen = set();
for num in lst: if num in seen: return num;
seen.add(num);
returnNone
Write a Java function to find the minimum value in an array of integers
public intfindMinValue(int[] arr) {
int min = arr[0];
for (int i = 1;
i < arr.length;
i++) {
if (arr[i] < min) {
min = arr[i];
}
}
return min;
}
Write a Python function to find the longest common prefix in a list of strings
