Mphasis Pyspark Developer Interview Questions and Answers

Basic python coding, list, dict, generators etc

Q1. Salary negotiation
Add your answer

Q1. React hooks, nodejs routing, metadata, aws deployment process, microservices, dom, event loop
Add your answer

Q1. Run time polymorphism code
Add your answer
Q2. Linked list code
Add your answer
Q3. Deep copy shallow copy differences
Ans. 
Deep copy creates a new copy of an object with its own unique memory space, while shallow copy creates a new object that references the same memory locations as the original object.
• Deep copy duplicates all nested objects, while shallow copy only duplicates the references to nested objects.

• Deep copy ensures that changes to the copied object do not affect the original object, while shallow copy may lead to unintended sid...read more
Answered by AI
Add your answer

Q1. More deep questions about polymorphism code
Add your answer
Q2. Code for interchange of strings without strcpy
Ans. 
Use a loop to swap characters of two strings without using strcpy function.
• Create two arrays of characters to store the strings

• Use a loop to iterate through each character of the strings and swap them

• Ensure to handle cases where strings have different lengths
Answered by AI
Add your answer

It's walkin, so they conducted 1 technical mcqs round.

Q1. Multi threading
Add your answer
Q2. Internal working of hashmap
Ans. 
HashMap in Java is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values based on keys.
• HashMap uses an array of buckets to store key-value pairs.

• Keys are hashed to determine the index in the array where the key-value pair will be stored.

• In case of hash collisions, a linked list or a balanced tree is used to store multiple key-value pairs in the same bucket.

• HashMap allows null keys...read more
Answered by AI
Add your answer
Q3. Spring batch related
Add your answer
Q4. Non repeating characters in a array
Ans. 
Function to find and return all non-repeating characters in an array of strings.
• Iterate through the array and count the occurrences of each character using a HashMap.

• Then iterate through the array again and check if the count of each character is 1, if so add it to the result list.

• Return the list of non-repeating characters.
Answered by AI
Add your answer
Q5. 3rd highest salary
Ans. 
To find the 3rd highest salary in a database, we can use a SQL query with the 'LIMIT' and 'OFFSET' keywords.
• Use a SQL query with 'ORDER BY salary DESC' to sort the salaries in descending order.

• Use 'LIMIT 1 OFFSET 2' to skip the first two highest salaries and retrieve the third highest salary.

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 2;
Answered by AI
Add your answer
Q6. Qualifier vs primary
Ans. 
A qualifier in Java is used to specify additional information about a primary, which is the main data type or variable.
• A primary in Java is the main data type or variable, while a qualifier provides additional information about the primary.

• Qualifiers can be used to modify the behavior or characteristics of a primary.

• For example, in Java, 'final' is a qualifier that can be used to make a variable constant.
Answered by AI
Add your answer
Q7. Controller vs restcontroller
Ans. 
The main difference is that @RestController is a specialized version of @Controller that is used for RESTful web services.
• Both @Controller and @RestController are used in Spring MVC to handle HTTP requests, but @RestController is specifically used for RESTful web services.

• @Controller is used to create web pages, while @RestController is used to return data in JSON or XML format.

• @RestController is a convenience annotati...read more
Answered by AI
Add your answer
Q8. Spring boot annotataions
Add your answer
Q9. Oops concepts with examples
Ans. 
OOP concepts include inheritance, encapsulation, polymorphism, and abstraction.
• Inheritance: Allows a class to inherit properties and behavior from another class. Example: class Dog extends Animal.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: private variables with public getter and setter methods.

• Polymorphism: Ability for objects to be treated as instances of their paren...read more
Answered by AI
Add your answer
Q10. Spring batch configuration
Add your answer
Q11. They covered all java, spring and Microservices
Add your answer

Q1. Microservices architecture
Add your answer
Q2. How do Microservices communicate
Ans. 
Microservices communicate with each other through various communication protocols like HTTP, messaging queues, and gRPC.
• Microservices can communicate over HTTP using RESTful APIs.

• Messaging queues like RabbitMQ or Kafka can be used for asynchronous communication between microservices.

• gRPC is a high-performance, open-source RPC framework that can be used for communication between microservices.

• Service discovery mechanism...read more
Answered by AI
Add your answer
Q3. How to access the Microservice end point
Ans. 
Microservice endpoints can be accessed using HTTP requests with the appropriate URL
• Use HTTP methods like GET, POST, PUT, DELETE to interact with the microservice

• Construct the URL with the base URL of the microservice and the specific endpoint path

• Include any necessary headers or parameters in the request for authentication or data filtering
Answered by AI
Add your answer
Q4. Why we use microservices
Ans. 
Microservices allow for modular, scalable, and flexible software development by breaking down applications into smaller, independent services.
• Microservices enable easier maintenance and updates as each service can be developed, deployed, and scaled independently.

• They improve fault isolation, as failures in one service do not necessarily affect the entire application.

• Microservices promote agility and faster time-to-mark...read more
Answered by AI
Add your answer

Q1. Explain architecture of your project
Add your answer
Q2. Some questions on Java, Spring Boot and sql
Add your answer

Q1. Project flow and some behavioural questions
Add your answer
Q2. Project contribution of yours
Ans. 
Developed a web application for tracking employee attendance and performance
• Implemented user authentication and authorization using Spring Security

• Utilized Hibernate for database interaction and data persistence

• Designed and developed RESTful APIs for frontend integration

• Used AngularJS for frontend development to create interactive user interfaces
Answered by AI
Add your answer

Q1. Basic formalities before offer release
Add your answer

A standard online test conducted through one of the testing platforms.

Q1. Java 8 features
Add your answer
Q2. Rest API
Add your answer
Q3. Java 8 coding problem
Add your answer
Q4. Collections
Add your answer

Q1. It was based on my previous project
Add your answer

Q1. Discussion about my previous project
Add your answer
Q2. Question on html, css, javascript & react
Add your answer
Q3. Explain about promises
Ans. 
Promises are objects representing the eventual completion or failure of an asynchronous operation.
• Promises are used to handle asynchronous operations in JavaScript.

• They can be in one of three states: pending, fulfilled, or rejected.

• Promises can be chained using .then() to handle success and .catch() to handle errors.

• Example: const myPromise = new Promise((resolve, reject) => { ... });
Answered by AI
Add your answer
Q4. Use state, context api
Add your answer
Q5. Box modelling in css, css pre processors
Ans. 
Box model in CSS refers to the way elements are rendered in a web page. CSS preprocessors like SASS or LESS help streamline CSS development.
• Box model in CSS includes content, padding, border, and margin.

• CSS preprocessors like SASS or LESS allow for variables, nesting, and mixins to be used in CSS.

• Example: box-sizing: border-box; in CSS changes the box model to include padding and border in the element's total width and
Answered by AI
Add your answer

Q1. Can we call future method from batch class
Ans. 
Yes, future methods can be called from a batch class in Salesforce.
• Future methods can be called from batch classes to perform asynchronous processing.

• This can be useful for offloading long-running tasks to future methods to avoid hitting governor limits.

• Example: Calling a future method from a batch class to update records in Salesforce asynchronously.
Answered by AI
Add your answer
Q2. What's the use of @track decorator. Is it mandatory to explicitly use it? If yes, for which use case?
Ans. 
The @track decorator in Salesforce is used to track changes to a property in a Lightning web component.
• Used to make a property reactive and trigger re-renders when its value changes

• Not mandatory but recommended for properties that need to be reactive

• Use @track when you want changes to a property to be reflected in the UI
Answered by AI
Add your answer
Q3. When does APEX CPU Limit Exceeded error happens. What's the best practice to avoid getting this error?
Ans. 
APEX CPU Limit Exceeded error happens when code consumes too much CPU time. Best practices include optimizing code, reducing loops, and using asynchronous processing.
• Avoid using nested loops and optimize code for better performance

• Use asynchronous processing like @future or Queueable to offload CPU intensive tasks

• Limit the use of SOQL queries inside loops to reduce CPU consumption
Answered by AI
Add your answer
Q4. When does Mixed DML Exception occurs?
Ans. 
Mixed DML Exception occurs when DML operations are performed on setup and non-setup objects in a single transaction.
• Occurs when DML operations are performed on both setup and non-setup objects in a single transaction

• Setup objects include User, Profile, PermissionSet, etc.

• Non-setup objects include custom objects, standard objects like Account, Contact, etc.
Answered by AI
Add your answer
Q5. Debug the following code: var a=10; function abc() { console.log(a); var a=2; } abc();
Ans. 
The code will output 'undefined' because variable 'a' is hoisted within the function.
• Variable 'a' is hoisted to the top of the function scope, so when 'console.log(a)' is called, 'a' is undefined.

• To fix this, move the declaration of 'var a=2;' above the 'console.log(a);' statement.
Answered by AI
Add your answer
Q6. Write a SOQL query to fetch the values of description field from the Account. Why does "the description field cannot be filtered in the query call"?
Ans. 
SOQL query to fetch description field from Account and reason for inability to filter
• SOQL query: SELECT Description FROM Account

• Description field is not filterable because it is a long text field

• Long text fields cannot be filtered in SOQL queries
Answered by AI
Add your answer