50+ TCS Interview Questions and Answers

Java Developer interview questions on beans, functional interfaces, SQL queries, hibernate, and more.

• Scope of beans refers to the visibility of a bean within an application context.

• Functional interfaces have only one abstract method and can be used as lambda expressions.

• Classes cannot be private, but their constructors can be.

• SQL query to find employees of a particular department table: SELECT * FROM employees WHERE department = 'department_name'

• Cascading in Hibernate refers ...read more

The number of columns that can be created in a table depends on the database management system being used.

• The limit varies depending on the DBMS

• For MySQL, the limit is 4096 columns per table

• For Oracle, the limit is 1000 columns per table

• The number of columns can also be limited by the available memory and disk space

This program sorts the characters of a string in descending order.

• Convert the string to a character array

• Sort the character array in descending order

• Convert the sorted character array back to a string

To increase server performance for a million connections per sec, we can optimize hardware, use load balancing, and implement caching.

• Optimize hardware by upgrading RAM, CPU, and network interface cards

• Use load balancing to distribute traffic across multiple servers

• Implement caching to reduce server load and improve response time

• Use a content delivery network (CDN) to serve static content

• Use compression to reduce the size of data transmitted over the network

Design patterns are reusable solutions to common software problems. One example is the Singleton pattern.

• Creational patterns: Singleton, Factory, Abstract Factory, Builder

• Structural patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy

• Behavioral patterns: Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor

• Singleton pattern ensures a class has only one instance, and provides a globa...read more

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 a problem

• Encapsulation: Objects encapsulate data and behavior. Example: Car object with properties like color and methods like start()

• Inheritance: Objects can inherit attributes and methods from other objects. Example: Animal class with Dog and Cat subclasses

• Polymorphism: Objects c...read more

Data structures are ways to organize and store data efficiently in a computer.

• Data structures are used to store and organize data in a way that makes it easy to access and manipulate.

• Examples of data structures include arrays, linked lists, stacks, queues, trees, and graphs.

• For example, an array is a data structure that stores a collection of elements in a contiguous block of memory.

• A linked list is a data structure where each element points to the next element in the list.

• A ...read more

OOPs concepts are the fundamental principles of object-oriented programming.

• Encapsulation - binding data and functions together

• Inheritance - creating new classes from existing ones

• Polymorphism - ability of objects to take on multiple forms

• Abstraction - hiding implementation details from users

The question is about a tester interview and includes various topics such as output manipulation, finding largest and smallest elements, OOPs concepts in Python, difference between find_element and find_elements, negative indexing in Python, and list comprehension.

• 1. The desired output is 'TTHHEE'.

• 2. Find the largest and smallest elements from a given list.

• 3. Discuss the OOPs concepts used in Python.

• 4. Explain the difference between find_element and find_elements.

• 5. Explain h...read more

Microservice design patterns are architectural patterns that help in designing and implementing microservices.

• Service Decomposition

• API Gateway

• Service Registry

• Circuit Breaker

• Saga Pattern

The size of routing table is determined by the number of network prefixes and the number of routes.

• The size of routing table is directly proportional to the number of network prefixes and the number of routes.

• The size of routing table can be estimated by analyzing the number of unique IP addresses and the number of routing protocols used.

• The size of routing table can be reduced by summarizing routes and using route aggregation.

• The size of routing table can also be affected by...read more

Master database is the primary database that stores all the important data of an organization.

• Master database is the central repository of all the important data of an organization

• It is used to store and manage critical data such as customer information, financial data, and employee records

• It is usually the most secure and highly available database in an organization

• Examples of master databases include Oracle, SQL Server, and MySQL

Java is a popular backend language, polymorphism allows objects to be treated as instances of their parent class, reverse string by iterating through characters.

• Java is commonly used in backend development for its robustness and scalability.

• Polymorphism in OOP allows objects to be treated as instances of their parent class, enabling flexibility and reusability.

• To reverse a string, iterate through the characters from the end to the beginning and append them to a new string.

Data types in JavaScript include number, string, boolean, object, function, undefined, and null.

• Number - represents numeric data, e.g. 10, 3.14

• String - represents textual data, e.g. 'hello', '123'

• Boolean - represents true or false values, e.g. true, false

• Object - represents complex data structures, e.g. { key: 'value' }

• Function - represents executable code, e.g. function() { }

• Undefined - represents a variable that has not been assigned a value

• Null - represents an intentional ...read more

A shell script with arguments included

• Start with a shebang line to specify the shell interpreter

• Define variables to store the arguments passed to the script

• Use conditional statements to handle different scenarios based on the arguments

• Use loops to iterate over multiple arguments

• Add comments to explain the purpose of the script and each section

The old environment had a background in SCCM.

• The old environment utilized SCCM for software deployment and updates.

• SCCM was also used for inventory management and reporting.

• The SCCM infrastructure was configured with multiple distribution points for efficient content delivery.

• The old environment may have had custom scripts or packages created for specific software deployments.

• SCCM was likely integrated with Active Directory for user and device management.

Python class design for Selenium test class involves creating a class with methods to interact with web elements and perform test actions.

• Create a class for the test case with setup and teardown methods

• Use instance variables to store web element locators

• Implement test methods to perform actions like clicking, entering text, verifying text, etc.

• Use Selenium WebDriver to interact with the browser and web elements

Artificial Intelligence (AI) is the simulation of human intelligence processes by machines, especially computer systems.

• AI involves the development of algorithms that can perform tasks that typically require human intelligence, such as visual perception, speech recognition, decision-making, and language translation.

• Machine learning is a subset of AI that focuses on the development of algorithms that allow computers to learn from and make predictions or decisions based on data...read more

Patching old env involves identifying vulnerabilities, prioritizing patches, testing, and deploying.

• Identify vulnerabilities in the old environment

• Prioritize patches based on severity and impact

• Test patches in a non-production environment before deploying

• Deploy patches during scheduled maintenance windows

• Monitor the environment for any issues post-patching

Designing an MQTT test framework from scratch

• Understand the requirements for testing MQTT protocol

• Choose a programming language for implementation

• Design test cases for different scenarios

• Implement message publishing and subscribing functionalities

• Include error handling mechanisms

• Consider scalability and performance testing

Program to group 0's, 1's, and 2's in an array of strings.

• Iterate through the array and count the occurrences of 0's, 1's, and 2's.

• Create a new array of strings with the grouped numbers in the desired order.

• Example: Input array ['1', '0', '2', '1', '0'], Output array ['0', '0', '1', '1', '2']

Understanding infrastructure for an organization is crucial for a Project Manager to ensure successful project delivery.

• Infrastructure refers to the physical components and systems necessary for an organization to operate efficiently.

• Project Managers need to understand the existing infrastructure of an organization to plan and execute projects effectively.

• Examples of infrastructure include hardware, software, networks, data centers, and communication systems.

• Infrastructure un...read more

I have experience handling various types of projects with budgets ranging from small to large.

• Managed IT projects with budgets ranging from $10,000 to $1,000,000

• Led construction projects with budgets exceeding $5,000,000

• Handled marketing campaigns with budgets as low as $1,000

Python is a versatile scripting language used for automation, web development, data analysis, and more.

• Python is easy to learn and read, making it a popular choice for scripting.

• It has a large standard library with built-in modules for various tasks.

• Python supports multiple programming paradigms, including procedural, object-oriented, and functional programming.

• It offers extensive third-party libraries like Selenium, PyTest, and requests for testing purposes.

• Python's syntax e...read more

Closures are functions that have access to variables from their containing scope even after the scope has closed.

• Closures allow functions to access variables from their outer function even after the outer function has finished executing.

• They are commonly used in event handlers, callbacks, and asynchronous programming.

• Closures help in maintaining state in functional programming.

Virtual DOM is a lightweight copy of the actual DOM used for efficient updates in web development.

• Virtual DOM is a concept used in frameworks like React to improve performance by minimizing actual DOM manipulations.

• When changes are made to the virtual DOM, a comparison is done with the actual DOM to determine the minimal updates needed.

• This approach reduces the number of costly DOM operations, resulting in faster rendering and improved user experience.

A signal is considered high speed when it has a fast data transfer rate.

• High-speed signals typically have data transfer rates above a certain threshold, such as 1 Gbps.

• These signals require careful design considerations to minimize signal degradation and ensure reliable transmission.

• Examples of high-speed signals include USB 3.0, HDMI, PCIe, and DDR4 memory interfaces.

The current project architecture is a microservices-based system with a containerized deployment using Kubernetes.

• Microservices architecture allows for modular and scalable development.

• Containerization with Kubernetes enables efficient deployment and management of services.

• Use of service mesh for communication between microservices.

• Integration of monitoring and logging tools for observability.

• Implementation of CI/CD pipelines for automated testing and deployment.

Threading is a programming technique that allows multiple tasks to run concurrently within a single process.

• Threading allows for parallel execution of tasks within a program.

• Threads share the same memory space, allowing for efficient communication between tasks.

• Examples of threading include creating separate threads for handling user input and updating the UI in a GUI application.

PMP certification obtained in 2018

• Obtained PMP certification in 2018

• Continuously pursuing professional development through relevant certifications

• Certifications demonstrate commitment to project management excellence

To read data from Excel, we can use libraries like Apache POI or Openpyxl.

• Use Apache POI library in Java to read Excel files

• Use Openpyxl library in Python to read Excel files

• Identify the Excel file path and create a FileInputStream object

• Create an instance of Workbook class and load the Excel file

• Access the desired sheet and iterate through rows and columns to read data

React code for a simple counter

• Create a functional component for the counter

• Use useState hook to manage the count state

• Render the count value and buttons to increment and decrement the count

Reverse a string and find the maximum number in the string.

• Iterate through the string in reverse order to reverse it.

• Use a variable to keep track of the maximum number found while iterating through the string.

• Convert each character to a number and check if it is greater than the current maximum number.

Callback hell is a situation in asynchronous programming where multiple nested callbacks make the code difficult to read and maintain.

• Occurs when multiple asynchronous operations are nested within each other

• Leads to deeply nested code structure which is hard to understand and maintain

• Can be avoided by using promises, async/await, or libraries like async.js

OOPs concept stands for Object-Oriented Programming concepts which include principles like inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementation details and showing only the necessary f...read more

I have handled various types of projects including construction, software development, event planning, and marketing campaigns.

• Construction projects

• Software development projects

• Event planning projects

• Marketing campaign projects

API clients can pose challenges due to varying levels of technical expertise and understanding of the API.

• Different API clients may have different levels of technical expertise, leading to misunderstandings or misinterpretations of the API documentation.

• API clients may not fully understand the capabilities and limitations of the API, resulting in inefficient or incorrect usage.

• Managing multiple API clients can be complex, especially when updates or changes to the API are made...read more

Business analysts use various tools to analyze data and communicate with stakeholders.

• Microsoft Excel for data analysis and reporting

• Jira for project management and tracking

• Lucidchart for creating process flow diagrams

• Tableau for data visualization

• Confluence for documentation and collaboration

Data lake is a centralized repository for storing structured and unstructured data, while mesh is a network of interconnected services.

• Data lake stores raw data in its native format, while mesh connects various services and applications.

• Data lake is used for data storage and analytics, while mesh is used for communication and integration.

• Examples of data lake technologies include Amazon S3 and Hadoop, while examples of mesh technologies include Istio and Linkerd.

Event loop is a mechanism in programming that allows for asynchronous execution of code by managing the order of operations.

• Event loop is commonly used in JavaScript to handle asynchronous operations.

• It allows for non-blocking I/O operations by continuously checking the event queue for tasks to execute.

• Event loop ensures that tasks are executed in the order they were added to the queue.

• Example: setTimeout() function in JavaScript uses event loop to schedule a function to run ...read more

Function to find duplicates in an array of integers and return a list of unique duplicates.

• Iterate through the array and keep track of elements seen before using a hash set.

• If an element is already in the hash set, add it to the result list.

• Return the list of unique duplicates found.

The project utilized various AWS services for data storage, processing, and analysis.

• S3 for data storage

• EC2 for computing resources

• Glue for ETL processes

• Sagemaker for machine learning models

• Athena for querying data in S3

Sort a given string array in alphabetical order

• Use a sorting algorithm like quicksort or mergesort

• Consider using built-in sorting functions in programming languages

• Ensure the sorting is case-sensitive unless specified otherwise

Check if a string is a palindrome

• Iterate through the string from both ends and compare characters

• Ignore spaces and punctuation while checking for palindrome

• Convert string to lowercase for case-insensitive comparison

A framework is a set of guidelines, libraries, and tools that help in developing and organizing code for software testing.

• Framework provides a structure for test automation

• It includes reusable components, libraries, and utilities

• Frameworks can be data-driven, keyword-driven, or hybrid

• Examples: Selenium WebDriver for web testing, Appium for mobile testing

OSPF states are the different stages a router goes through while establishing and maintaining a neighbor relationship.

• OSPF states include Down, Init, 2-Way, Exstart, Exchange, Loading, and Full

• In the Down state, the router has not yet established a neighbor relationship

• In the Init state, the router has sent a Hello packet but has not received a response

• In the 2-Way state, the router has received a Hello packet from a neighbor

• In the Exstart state, the routers exchange their in...read more

Vue.js is a progressive JavaScript framework for building user interfaces.

• Reactive data binding

• Component-based architecture

• Virtual DOM

• Directives

• Computed properties

• Event handling

• Routing

• Vuex state management

• Server-side rendering

Developed a real-time data processing system for analyzing customer behavior

• Designed and implemented data pipelines using Apache Kafka and Spark

• Optimized data processing algorithms to handle large volumes of streaming data

• Collaborated with data scientists to integrate machine learning models into the system

KPI's in retail are key performance indicators used to measure the success of a retail business.

• Sales revenue

• Customer satisfaction

• Inventory turnover rate

• Average transaction value

• Conversion rate

• Gross margin

• Foot traffic

• Return on investment (ROI)

API automation is the process of using software to execute pre-scripted tests on APIs to ensure they function correctly.

• API automation involves writing scripts to interact with APIs and validate their responses

• It helps in automating the testing of API endpoints for functionality, reliability, and performance

• Tools like Postman, SoapUI, and RestAssured are commonly used for API automation

• API automation can be used for regression testing, load testing, and integration testing of...read more