40+ Vamso Biotec Interview Questions and Answers

The question asks for programs on Java 8 and 11, multithreading, collections, design patterns, SOLID principles, Spring MVC and Boot, and REST API.

• Java 8 and 11 programs: Provide examples of programs written in Java 8 and 11.

• Multithreading: Discuss the concept of multithreading and provide examples of how it can be implemented in Java.

• Collections: Explain the different types of collections in Java and their usage.

• Design patterns: Discuss commonly used design patterns in softw...read more

I have worked with design patterns such as Singleton, Factory, Observer, and Strategy in my projects.

• Singleton pattern was used to ensure only one instance of a class is created.

• Factory pattern was used to create objects without specifying the exact class of object that will be created.

• Observer pattern was used to define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.

• Strategy pattern wa...read more

Use lambda function to print greater number

• Define a lambda function that takes two parameters

• Use the max() function inside the lambda to compare the two numbers

• Call the lambda function with two numbers to print the greater one

Use two threads to print numbers 1-10 in correct order

• Create two threads, one for printing odd numbers and one for printing even numbers

• Use synchronization mechanisms like mutex or semaphore to ensure correct order

• Example: Thread 1 prints 1, 3, 5, 7, 9 and Thread 2 prints 2, 4, 6, 8, 10

CompletableFuture is a class introduced in Java 8 to represent a future result of an asynchronous computation.

• CompletableFuture can be used to perform tasks asynchronously and then combine their results.

• It supports chaining of multiple asynchronous operations.

• It provides methods like thenApply, thenCompose, thenCombine, etc. for combining results.

• Example: CompletableFuture future = CompletableFuture.supplyAsync(() -> 10);

OOPs concept is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOPs stands for Object-Oriented Programming

• It focuses on creating objects that interact with each other to solve a problem

• Encapsulation, inheritance, polymorphism, and abstraction are key principles of OOPs

• HashMap in Java is a data structure that stores key-value pairs

• It uses hashing to store and retrieve elements efficiently

• E...read more

Yes, I am able to work in hybrid mode which involves a combination of remote and on-site work.

• Experienced in collaborating with remote team members using communication tools like Slack, Zoom, and Jira

• Comfortable with switching between working on-site and remotely based on project requirements

• Adaptable to different work environments and able to maintain productivity in both settings

JDK 8 features include lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to write code in a more concise and readable way.

• Functional interfaces enable the use of lambda expressions.

• Streams provide a way to work with sequences of elements efficiently.

• Default methods allow interfaces to have concrete methods.

• Date and Time API improvements.

Fibonacci series code in iterative and recursive methods

• Iterative method: Use a loop to calculate Fibonacci numbers

• Recursive method: Define a function that calls itself to calculate Fibonacci numbers

• Example for iterative method: int fib(int n) { int a = 0, b = 1, c; for(int i = 2; i <= n; i++) { c = a + b; a = b; b = c; } return b; }

• Example for recursive method: int fib(int n) { if(n <= 1) return n; return fib(n-1) + fib(n-2); }

Microservice architecture focuses on breaking down applications into smaller, independent services.

• Microservices are small, independent services that work together to form a complete application.

• Each microservice is responsible for a specific function or feature.

• Design patterns like API Gateway, Circuit Breaker, and Service Registry are commonly used in microservice architecture.

• Microservices communicate with each other through APIs.

• Scalability, fault tolerance, and flexibili...read more

Method references in Java 8 are a way to refer to methods or constructors without invoking them directly.

• Method references are shorthand notation for lambda expressions.

• They can be used to make code more concise and readable.

• There are four types of method references: static, instance, constructor, and arbitrary object.

• Example: list.forEach(System.out::println);

Call stack is a data structure that stores function calls in JavaScript, while event loop manages asynchronous operations.

• Call stack is a mechanism for managing function invocation in JavaScript.

• Functions are added to the call stack when they are invoked and removed when they are completed.

• Event loop is responsible for handling asynchronous operations in JavaScript.

• Event loop continuously checks the call stack and the callback queue to determine if there are any tasks to be e...read more

Index is a database structure that improves the speed of data retrieval. Types include clustered, non-clustered, and full-text.

• Index is a data structure that improves query performance by allowing faster data retrieval.

• Clustered index determines the physical order of data in a table.

• Non-clustered index is a separate structure that stores a copy of the indexed columns and a pointer to the actual data.

• Full-text index is used for text-based searches and allows for complex querie...read more

Transaction propagation in Hibernate allows the management of multiple database operations within a single transaction.

• Hibernate supports different transaction propagation modes such as REQUIRED, REQUIRES_NEW, SUPPORTS, MANDATORY, NOT_SUPPORTED, and NEVER.

• The propagation mode determines how the transaction should be handled when a method is called within an existing transaction.

• REQUIRED is the default propagation mode, where if a transaction exists, the method will join it, o...read more

OOPs concepts refer to Object-Oriented Programming 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 features.

Unit testing in C++ involves writing test cases for individual units of code to ensure they work as expected.

• Use a unit testing framework like Google Test or Catch2 to write and run test cases

• Create separate test files for each unit of code being tested

• Use assertions to check the expected behavior of the code under test

• Mock dependencies or use dependency injection to isolate units for testing

• Run tests regularly to catch regressions and ensure code quality

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• HashMap uses the hashCode() method of keys to calculate the hash value.

• HashMap provides constant-t...read more

ACID properties are a set of properties that ensure database transactions are processed reliably.

• ACID stands for Atomicity, Consistency, Isolation, and Durability.

• Atomicity ensures that a transaction is treated as a single, indivisible unit of work.

• Consistency ensures that a transaction brings the database from one valid state to another.

• Isolation ensures that concurrent transactions do not interfere with each other.

• Durability ensures that once a transaction is committed, it ...read more

Promises are used for a single async operation while observables are used for multiple async operations and can be cancelled.

• Promises are eager, meaning they start immediately upon creation.

• Observables are lazy, meaning they only start when subscribed to.

• Promises can only handle a single value or error, while observables can handle multiple values over time.

• Observables can be cancelled, while promises cannot.

• Promises are part of ES6, while observables are part of RxJS library...read more

Agile ceremonies are key meetings in Agile methodology where QA plays a crucial role in ensuring quality throughout the development process.

• QA participates in Agile ceremonies such as Sprint Planning, Daily Stand-ups, Sprint Review, and Sprint Retrospective to provide input on quality aspects.

• QA helps in defining acceptance criteria for user stories during Sprint Planning to ensure that the team understands the quality expectations.

• QA collaborates with developers during Daily...read more

Updating the scrum board involves adding, moving, and removing tasks to reflect the current status of the project.

• Regularly update the scrum board with the progress of tasks

• Move tasks from 'To Do' to 'In Progress' to 'Done' columns as they are worked on and completed

• Remove tasks that are no longer relevant or have been completed

• Ensure the team is aware of any changes made to the scrum board

To design a high-performance Cache API for multithreaded environment, follow these pointers:

• Use a concurrent hash map to store the cache data

• Implement a read-write lock to allow multiple threads to read simultaneously

• Use a thread-safe data structure for cache eviction policy

• Implement a cache loader to load data into the cache on demand

• Use a bounded cache to prevent memory overflow

• Implement a cache statistics collector to monitor cache usage

• Use a cache manager to manage the ca...read more

Story estimation techniques in Agile involve using relative sizing, planning poker, and t-shirt sizing.

• Relative sizing compares the size of one story to another to estimate effort.

• Planning poker involves team members individually estimating stories and then discussing differences.

• T-shirt sizing categorizes stories into small, medium, large, etc. based on complexity.

• Fibonacci sequence can be used for story points (1, 2, 3, 5, 8, 13, etc.).

SQL Joins are used to combine rows from two or more tables based on a related column between them.

• INNER JOIN: Returns rows when there is at least one match in both tables

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table

• FULL JOIN: Returns rows when there is a match in one of the tables

Deep dive into .NET Core and Angular

• NET Core is a cross-platform, open-source framework for building modern, cloud-based, internet-connected applications.

• Angular is a popular front-end framework for building dynamic web applications.

• Understanding the architecture, features, and best practices of both .NET Core and Angular is essential for developing robust and scalable applications.

• Integration of .NET Core backend with Angular frontend for creating full-stack applications.

• Uti...read more

Temp tables are used to store temporary data during a session. There are two types: local and global.

• Local temp tables are only accessible within the session that created them.

• Global temp tables are accessible to all sessions and are prefixed with ##.

• Temp tables are automatically dropped when the session that created them ends.

• Temp tables can improve performance by reducing the need for expensive queries or joins.

Query optimization involves identifying and improving the performance of database queries.

• Identify slow queries using profiling tools

• Analyze query execution plans to identify bottlenecks

• Optimize queries by rewriting them or adding indexes

• Use caching to reduce the number of queries

• Regularly monitor and tune the database for optimal performance

Enhancements can be categorized into three types: functional, technical, and performance.

• Functional enhancements improve the functionality of the system.

• Technical enhancements improve the technical aspects of the system.

• Performance enhancements improve the performance of the system.

• Examples of functional enhancements include adding new features or improving existing ones.

• Examples of technical enhancements include upgrading hardware or software components.

• Examples of performan...read more

BADi is a Business Add-In that allows customizations to SAP applications. BAPI is a Business Application Programming Interface for SAP.

• BADi is used to enhance the functionality of SAP applications without modifying the source code.

• BAPI is used to integrate SAP applications with other systems.

• BADi is implemented using ABAP code.

• BAPI is a set of standard interfaces for accessing SAP business objects.

• Examples of BADi include enhancing the functionality of SAP Sales and Distribut...read more

I have experience using a variety of testing tools such as Selenium, Jira, and TestRail.

• Selenium

• Jira

• TestRail

Spring MVC is a framework for building web applications in Java.

• Spring MVC is a part of the Spring Framework, which provides a model-view-controller architecture for developing web applications.

• It follows the MVC design pattern, where the model represents the data, the view represents the user interface, and the controller handles the requests and manages the flow of data.

• It provides features like request mapping, data binding, validation, and view resolution.

• Example: In a Sp...read more

Designing and analyzing a project involves creating a plan and evaluating its feasibility and effectiveness.

• Identify project goals and objectives

• Develop a detailed project plan including timelines and resources

• Conduct risk analysis and mitigation strategies

• Evaluate project outcomes and make adjustments as needed

Iterate through the array to find the second greatest number.

• Iterate through the array and keep track of the greatest and second greatest numbers.

• Compare each element with the current greatest and second greatest numbers.

• Update the second greatest number if a new number is found that is greater than the current second greatest but less than the greatest.

Use a sorting algorithm like bubble sort or quicksort to arrange elements in ascending order.

• Use a sorting algorithm like bubble sort, quicksort, or merge sort to rearrange elements in ascending order.

• For example, you can implement bubble sort to compare adjacent elements and swap them if they are in the wrong order.

• Another example is using quicksort to divide the array into smaller subarrays and recursively sort them.

Business Analysts analyze business processes and systems to provide solutions for improvement. SQL knowledge is often required.

• Business Analysts gather and analyze data to understand business needs and requirements

• They work with stakeholders to define project scope and objectives

• BA create detailed documentation of requirements and solutions

• SQL knowledge is beneficial for querying databases and analyzing data

A Business Analyst (BA) analyzes business processes, identifies needs, and recommends solutions. SQL is a programming language used for managing and querying databases.

• BA analyzes business processes to identify needs and recommend solutions

• BA works closely with stakeholders to gather requirements and define project scope

• SQL is a programming language used for managing and querying databases

• SQL allows users to retrieve and manipulate data stored in a database

• BA may use SQL to e...read more

Devops tools are software products that help automate the processes involved in software development, testing, and deployment.

• Popular Devops tools include Jenkins, Docker, Ansible, Kubernetes, and Git.

• These tools help in automating tasks like building, testing, and deploying software applications.

• They also facilitate collaboration between development and operations teams, leading to faster and more reliable software delivery.

• Devops tools are often used in conjunction with con...read more

End to end project flow involves planning, execution, monitoring, and closing of a project.

• Initiation: Define project scope, objectives, and deliverables.

• Planning: Create project plan, schedule, and budget.

• Execution: Implement project plan and deliver project deliverables.

• Monitoring: Track project progress, identify risks, and make necessary adjustments.

• Closing: Finalize project deliverables, obtain client approval, and close out project.

WFM process involves forecasting, scheduling, real-time management, and reporting to optimize workforce efficiency.

• Forecasting: predicting future workload and staffing needs

• Scheduling: creating employee schedules based on forecasted needs

• Real-time management: monitoring and adjusting schedules in real-time

• Reporting: analyzing data to improve future forecasting and scheduling

• Examples: call center staffing, retail store scheduling, healthcare staffing

Java has two types of beans: stateful and stateless beans.

• Stateful beans maintain conversational state with the client, while stateless beans do not.

• Stateful beans are typically used for long-running conversations, while stateless beans are used for short-lived operations.

• Examples of stateful beans include session beans, while examples of stateless beans include message-driven beans.