20+ EVIO Interview Questions and Answers

Use SQL query to count number of reportees for each manager and filter out those with atleast 5 reportees.

• Write a SQL query to count number of reportees for each manager using GROUP BY clause

• Add HAVING clause to filter out managers with atleast 5 reportees

• Example: SELECT managerId, COUNT(id) AS num_reportees FROM table_name GROUP BY managerId HAVING num_reportees >= 5

Some commonly used Python libraries for Data Analysts are Pandas, NumPy, Matplotlib, and Scikit-learn.

• Pandas - used for data manipulation and analysis

• NumPy - used for numerical computing and working with arrays

• Matplotlib - used for data visualization

• Scikit-learn - used for machine learning and data mining

Use libraries like pandas and dask to efficiently manage large datasets in Python.

• Use pandas library for data manipulation and analysis.

• Use dask library for parallel computing and out-of-core processing.

• Optimize memory usage by loading data in chunks or using data types efficiently.

• Consider using cloud services like AWS S3 or Google BigQuery for storing and processing large datasets.

Union combines and removes duplicates, Union All combines without removing duplicates

• Union combines result sets and removes duplicates

• Union All combines result sets without removing duplicates

• Union is slower than Union All as it involves removing duplicates

• Example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2;

• Example: SELECT column1 FROM table1 UNION ALL SELECT column1 FROM table2;

Coalesce function in SQL is used to return the first non-null value in a list of expressions.

• Coalesce function takes multiple parameters and returns the first non-null value.

• It is commonly used to handle null values in SQL queries.

• Example: SELECT COALESCE(column_name, 'N/A') FROM table_name;

Use a test automation tool like Selenium or Appium to run test cases without compiling in Java.

• Choose a test automation tool that supports your application's technology stack.

• Write test cases in the tool's scripting language or record them using the tool's recorder.

• Execute the test cases using the tool's runner or integration with a continuous integration tool.

• View the test results and debug failures as needed.

Program to check if a string is an anagram

• Create a function that takes in two strings as input

• Remove all spaces and convert both strings to lowercase

• Sort both strings and compare if they are equal to determine if they are anagrams

Python program to find the most occurred number in a sequence

• Iterate through the sequence and count the occurrences of each number using a dictionary

• Find the number with the highest count in the dictionary

• Handle edge cases like empty sequence or multiple numbers with the same highest count

React lifecycle methods are special methods that are automatically called by React at specific points in a component's life cycle.

• React components have several lifecycle methods such as componentDidMount, componentDidUpdate, componentWillUnmount, etc.

• These methods allow developers to perform actions at specific points in a component's life cycle, such as fetching data, updating the UI, or cleaning up resources.

• Understanding and utilizing these lifecycle methods is crucial for...read more

Mean, median, and mode are measures of central tendency in statistics.

• Mean is the average of a set of numbers, calculated by summing all the values and dividing by the total count.

• Median is the middle value in a sorted list of numbers. If there is an even number of values, it is the average of the two middle values.

• Mode is the value that appears most frequently in a set of numbers. It can be a single value or multiple values.

My strengths include strong analytical skills, attention to detail, and the ability to work well in a team.

• Strong analytical skills - able to analyze complex data sets and derive meaningful insights

• Attention to detail - meticulous in ensuring data accuracy and quality

• Team player - collaborate effectively with colleagues to achieve common goals

Spark runs in the background using a cluster manager to allocate resources and schedule tasks.

• Spark uses a cluster manager (such as YARN, Mesos, or Kubernetes) to allocate resources and schedule tasks.

• Tasks are executed by worker nodes in the cluster, which communicate with the driver program.

• The driver program coordinates the execution of tasks and manages the overall workflow.

• Spark's DAG scheduler breaks the job into stages and tasks, optimizing the execution plan.

• Spark's e...read more

My CGPA is 3.8 out of 4.0.

• My CGPA is 3.8, which is considered high in my university.

• I have consistently maintained a high CGPA throughout my academic career.

• I have received several academic awards based on my CGPA.

• My CGPA reflects my dedication and hard work towards my studies.

To find the middle number in a linked list.

• Traverse the linked list using two pointers, one moving twice as fast as the other.

• When the fast pointer reaches the end, the slow pointer will be at the middle node.

• If the linked list has even number of nodes, there will be two middle nodes. Return either one.

OOPS (Object-Oriented Programming) is a programming paradigm based on the concept of objects, which can contain data and code.

• OOPS focuses on creating objects that interact with each other to solve complex problems

• Key principles include encapsulation, inheritance, polymorphism, and abstraction

• Encapsulation ensures that the internal state of an object is hidden from the outside world

• Inheritance allows a class to inherit properties and behavior from another class

• Polymorphism en...read more

The shape of a normal distribution is bell-shaped and symmetrical.

• A normal distribution has a peak at the mean and tails that extend to infinity in both directions.

• The distribution is symmetrical, meaning that the left and right halves mirror each other.

• The standard deviation determines the spread or width of the distribution.

• Many natural phenomena and measurements in various fields follow a normal distribution.

• Examples include heights and weights of individuals, test scores,...read more

States in Flutter are the data values that can change during the lifetime of a widget.

• States are used to manage the data that changes over time in a Flutter application.

• There are two types of states in Flutter: Stateful and Stateless.

• Stateful widgets have mutable state that can change over time, while stateless widgets are immutable.

• Examples of states in Flutter include user input, network requests, and animations.

I manage states by using state management libraries like Redux and MobX, and by following best practices like separating UI and business logic.

• Use state management libraries like Redux or MobX to centralize and manage application state

• Follow best practices like separating UI and business logic to keep states manageable and maintainable

• Utilize local component state for simple and isolated state management within components

Drawing application is a software used for creating technical drawings and illustrations.

• Drawing applications are used in various fields like engineering, architecture, and graphic design.

• They allow users to create precise and accurate drawings with tools like rulers, grids, and measurement tools.

• Some popular drawing applications include AutoCAD, SolidWorks, and Adobe Illustrator.

• They also allow for easy editing and modification of drawings.

• Drawing applications can be used fo...read more

Stacks are a data structure that follows the Last In First Out (LIFO) principle.

• Elements are added and removed from the top of the stack

• Common operations include push (add element) and pop (remove element)

• Stacks can be implemented using arrays or linked lists

• Examples of stack usage include function call stack and undo/redo functionality in text editors

The STAR method is a structured way to respond to behavioral interview questions by discussing the Situation, Task, Action, and Result.

• Situation - Describe the context or background of the situation you were in.

• Task - Explain the specific task or goal you needed to accomplish.

• Action - Outline the actions you took to address the situation or task.

• Result - Share the outcome of your actions and any lessons learned.

• Example: Situation - During a team project, Task - I was assigned...read more

CTEs are named temporary result sets; subqueries are nested queries. Both help organize complex SQL queries.

• CTEs (Common Table Expressions) are defined using the WITH clause, while subqueries are embedded within SELECT, INSERT, UPDATE, or DELETE statements.

• CTEs can be referenced multiple times within a query, whereas subqueries can only be used once.

• Example of CTE: WITH SalesCTE AS (SELECT * FROM Sales) SELECT * FROM SalesCTE;

• Example of Subquery: SELECT * FROM Sales WHERE Sal...read more