40+ Vismaya Rocks Interview Questions and Answers

To create an EC2 instance using Terraform, define the necessary resources in a Terraform configuration file and run 'terraform apply'.

• Write a Terraform configuration file with the necessary resources, such as 'aws_instance' for EC2 instance.

• Specify the required parameters like 'ami', 'instance_type', 'subnet_id', etc.

• Run 'terraform init' to initialize the working directory.

• Run 'terraform plan' to see the execution plan.

• Run 'terraform apply' to create the EC2 instance.

• Verify t...read more

To copy a commit from one branch to another, use the git cherry-pick command.

• Checkout the branch where you want to copy the commit

• Find the commit hash of the commit you want to copy

• Run 'git cherry-pick ' to apply the commit to the current branch

git remote is used to manage remote repositories. git fetch is used to download changes from a remote repository.

• git remote is used to manage remote repositories

• git fetch is used to download changes from a remote repository

• git remote add is used to add a new remote repository

• git remote -v shows the list of remote repositories

• git fetch downloads changes from a remote repository

• git pull fetches and merges changes from a remote repository

• git push pushes changes to a remot...read more

Injections and attacks can be handled by implementing security measures and regularly updating software.

• Implement security measures such as firewalls, intrusion detection systems, and access controls

• Regularly update software and apply security patches

• Conduct regular security audits and penetration testing

• Train employees on security best practices and conduct background checks

• Use encryption to protect sensitive data

• Monitor network traffic for suspicious activity

Creating a pipeline through script involves defining stages, tasks, and triggers in a script file.

• Define stages for each step in the pipeline

• Define tasks for each stage, such as building, testing, and deploying

• Define triggers for each stage, such as manual or automatic triggers

• Use a scripting language such as YAML or JSON to define the pipeline

• Examples: Jenkinsfile for Jenkins, azure-pipelines.yml for Azure DevOps

Docker image has 3 layers: Base, Dependencies and Application.

• Base layer contains the OS and other system-level libraries.

• Dependencies layer contains the libraries and packages required by the application.

• Application layer contains the code and files specific to the application.

• Each layer is read-only and builds on top of the previous layer.

• Changes made to one layer do not affect the other layers.

• This layering approach makes Docker images lightweight and easy to share.

A fault domain is a logical group of hardware components that share a common power source and network switch.

• Fault domains are used to ensure high availability and fault tolerance in distributed systems.

• By distributing resources across fault domains, system failures can be isolated and minimized.

• Examples of fault domains include racks in a data center or availability zones in a cloud provider.

• In the event of a power outage or network failure in one fault domain, the system ca...read more

Webhooks in Jenkins are a way to trigger a build or perform an action in response to an external event.

• Webhooks allow Jenkins to receive notifications from external systems.

• They are typically used to trigger a build when a code repository is updated.

• Webhooks can be configured to send JSON or XML payloads to Jenkins.

• Jenkins can parse the payload and take actions based on the received data.

• Webhooks can be set up for various events like code commits, pull requests, etc.

To login docker registry, use the docker login command with the registry URL, username, and password.

• Use the docker login command followed by the registry URL

• Enter the username and password when prompted

• Example: docker login myregistry.com -u username -p password

Pointer is a variable that stores the memory address of another variable. Used for dynamic memory allocation and accessing data structures.

• Pointers are used to access and manipulate memory addresses directly.

• Example: int *ptr; ptr = # *ptr = 10; // num now equals 10

• Reverse Link list: Reverses the order of nodes in a linked list.

• String concatenation: Combining two or more strings into a single string.

• Communication protocols i2c v/s SPI: I2C is slower but uses fewer pins, SPI i...read more

React JS is a JavaScript library for building user interfaces on web browsers, while React Native is a framework for building mobile applications using React.

• React JS is used for web development, while React Native is used for mobile app development.

• React JS renders components to the DOM, while React Native renders components to native mobile elements.

• React JS uses HTML and CSS for styling, while React Native uses StyleSheet for styling mobile apps.

Improve React Native app performance by optimizing code, reducing unnecessary re-renders, using native modules, and implementing code splitting.

• Optimize code by removing unnecessary dependencies and using efficient algorithms

• Reduce unnecessary re-renders by using shouldComponentUpdate or React.memo

• Use native modules for performance-critical tasks to leverage platform-specific optimizations

• Implement code splitting to load only necessary components when needed

Git Gradle is not a specific tool or concept. Git is a version control system and Gradle is a build automation tool.

• Git is a distributed version control system used for tracking changes in source code during software development.

• Gradle is a build automation tool that is used to automate the building, testing, and deployment of software projects.

• Git and Gradle are often used together in software development workflows to manage source code and build processes.

Short term goal is to gain experience and improve skills. Long term goal is to become a senior accountant and contribute to the growth of the organization.

• Short term goal: Gain experience and improve skills

• Long term goal: Become a senior accountant and contribute to the growth of the organization

Python script to remove one list of numbers from other list using lambda and function.

• Define two lists of numbers

• Create a lambda function to filter out the numbers from the first list that are present in the second list

• Use the filter() function to apply the lambda function to the first list

• Print the filtered list

Cherry pick is a Git command used to select and apply specific commits from one branch to another.

• It allows developers to apply only the necessary changes to a branch without merging the entire branch.

• It can be useful in situations where a bug fix or feature needs to be applied to a specific branch without affecting other branches.

• Cherry picking can result in conflicts if the selected commit depends on other changes that are not present in the target branch.

• Example: git cherr...read more

I use tools like Altium Designer and Eagle for schematic design. These tools offer advanced features and a user-friendly interface.

• Altium Designer and Eagle are popular tools for schematic design in the industry.

• These tools offer advanced features such as real-time design synchronization, interactive routing, and 3D visualization.

• Altium Designer and Eagle have user-friendly interfaces that make it easier to create complex schematics and PCB layouts.

• They also provide extensive...read more

Questions on C++ and Java programming languages

• Run time polymorphism is achieved through virtual functions in C++

• Copy constructor is used to create a new object as a copy of an existing object in C++

• Java is an object-oriented programming language while C++ is a hybrid language

• JDK stands for Java Development Kit, JRE stands for Java Runtime Environment, and JVM stands for Java Virtual Machine

RTOS is more preferable for 32-bit controllers due to its real-time capabilities and task scheduling.

• RTOS provides real-time capabilities for time-sensitive applications

• RTOS offers task scheduling for efficient multitasking

• Bare metal programming may be suitable for simple applications with minimal overhead

Yocto is used to create custom Linux distributions tailored for specific embedded systems, providing flexibility and efficiency.

• Yocto allows for customization of Linux distributions for specific hardware requirements

• Enables easy integration of custom software components and drivers

• Provides a streamlined and efficient build process for embedded systems

• Offers a consistent and reproducible development environment

• Facilitates maintenance and updates for embedded devices

Memory in a system refers to the storage space where data and instructions are temporarily stored for processing.

• Memory is essential for the functioning of a computer system as it stores data and instructions that are currently being used by the CPU.

• There are different types of memory in a system, such as RAM (Random Access Memory) and ROM (Read-Only Memory).

• RAM is volatile memory that is used for temporary storage of data and instructions, while ROM is non-volatile memory th...read more

Calculate size of variable without library function

• Use the sizeof operator to calculate the size of a variable

• Multiply the size by the number of elements if it's an array

• Size of a struct is the sum of sizes of its members

• Size of a union is the size of its largest member

• Size of a pointer is platform-dependent

The algorithm used to fetch the library in my code involves importing the library and calling its functions.

• Import the library using the appropriate syntax for the programming language being used.

• Call the functions from the library as needed in the code.

• Ensure that the library is properly installed and configured on the system being used.

RTOS and real-time OS are the same thing, both referring to operating systems designed for real-time applications.

• RTOS is an acronym for Real-Time Operating System.

• Real-time OS is an alternative term for RTOS.

• Both RTOS and real-time OS refer to operating systems designed for real-time applications.

• Examples of RTOS include VxWorks, FreeRTOS, and QNX.

Microprocessors are integrated circuits that serve as the central processing unit (CPU) of a computer, handling instructions and data processing.

• Microprocessors are the brain of a computer, executing instructions and performing calculations.

• They are made up of millions of tiny components etched onto a single chip.

• Examples include Intel's Core series, AMD's Ryzen series, and ARM processors used in mobile devices.

• Microprocessors have evolved over time to become faster, more eff...read more

UC architecture stands for Unified Communications architecture, which integrates various communication tools into a single platform.

• UC architecture combines voice, video, messaging, and collaboration tools into a unified platform.

• It allows users to access all communication tools from a single interface.

• Examples of UC architecture include platforms like Microsoft Teams, Cisco Webex, and Zoom.

Data structures in C are used to store and organize data efficiently.

• Data structures in C include arrays, linked lists, stacks, queues, trees, and graphs.

• They help in performing operations like insertion, deletion, searching, and sorting.

• For example, an array is a data structure that stores a fixed-size sequential collection of elements of the same type.

8085 is an 8-bit microprocessor with a 16-bit address bus, while 8086 is a 16-bit microprocessor with a 20-bit address bus.

• 8085 is an 8-bit microprocessor, while 8086 is a 16-bit microprocessor.

• 8085 has a 16-bit address bus, while 8086 has a 20-bit address bus.

• 8085 has a maximum clock speed of 3 MHz, while 8086 has a maximum clock speed of 10 MHz.

• 8085 has a simpler instruction set compared to 8086, which has a more complex instruction set.

• 8085 is used in simpler applications ...read more

Python program to reverse a number

• Convert the number to a string

• Use string slicing to reverse the string

• Convert the reversed string back to an integer

PCIe configuration involves setting up the device's address space, interrupt handling, and power management.

• PCIe configuration space contains device-specific information.

• Configuration registers can be accessed through configuration transactions.

• Interrupt handling involves setting up MSI or MSI-X interrupts.

• Power management involves setting up power states and transitions.

A C program to print array of strings

• Declare an array of strings

• Initialize the array with strings

• Use a loop to print each string in the array

OOPs concepts are fundamental principles in object-oriented programming that help in organizing and designing code.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (class)

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

• Polymorphism: Ability for objects of different classes to respond to the same message in different ways

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

Use XOR operation to swap two variables without a third one

• Use XOR operation to swap two variables without a third one

• Example: a = 5, b = 10. a = a XOR b, b = a XOR b, a = a XOR b. Now a = 10, b = 5

CI/CD in Jenkins refers to continuous integration and continuous delivery/continuous deployment processes implemented using Jenkins automation server.

• CI/CD stands for Continuous Integration/Continuous Delivery or Continuous Deployment.

• In Jenkins, CI/CD involves automating the build, test, and deployment processes to deliver software more frequently and reliably.

• Continuous Integration involves automatically building and testing code changes as they are committed to the reposit...read more

Normalization is the process of organizing data in a database to eliminate redundancy and improve data integrity.

• Normalization helps in reducing data redundancy by breaking down a large table into smaller, more manageable tables.

• It ensures that each piece of data is stored in only one place, reducing the chances of inconsistencies.

• Normalization follows a set of rules called normal forms, such as First Normal Form (1NF), Second Normal Form (2NF), etc.

• Each normal form has speci...read more

Verilog code for a D flip-flop (D-FF) is a fundamental building block in digital design.

• D flip-flop stores one bit of data and is controlled by a clock signal.

• Verilog code for a D-FF typically includes a D input, clock input, and Q output.

• Example code: always @(posedge clk) begin Q <= D; end

Interrupt handling is a mechanism to handle asynchronous events in real-time systems.

• Interrupts are signals generated by hardware or software to interrupt the normal execution of a program.

• Interrupts are prioritized and handled by the Interrupt Service Routine (ISR).

• ISR saves the current state of the processor, executes the interrupt handler code, and restores the saved state.

• Interrupts can be edge-triggered or level-triggered, and can be handled synchronously or asynchronous...read more

Notice period refers to the amount of time an employee has to give before leaving a job.

• Notice period is the time frame between when an employee informs their employer of their intention to leave and their actual last day of work.

• It is typically stated in the employment contract and can vary from company to company.

• Notice periods can range from a few weeks to several months depending on the position and seniority of the employee.

• During the notice period, the employee is expec...read more

HashMap is a data structure that stores key-value pairs and allows for fast retrieval of values based on keys.

• HashMap uses hashing to store key-value pairs in an array of buckets.

• Each key is hashed to determine the index in the array where the value will be stored.

• HashMap allows for quick retrieval of values based on keys, making it efficient for lookups.

• HashMap in Java is an implementation of the Map interface and is part of the Java Collections Framework.

DevOps is a software development methodology that combines software development (Dev) with IT operations (Ops) to improve collaboration and efficiency.

• DevOps focuses on automating and streamlining the software development process.

• It emphasizes communication and collaboration between development and operations teams.

• DevOps aims to shorten the development lifecycle and provide continuous delivery of high-quality software.

• Tools commonly used in DevOps include Jenkins, Docker, An...read more

Classes are reference types, while structs are value types in Swift.

• Classes are reference types, stored in heap memory.

• Structs are value types, stored in stack memory.

• Classes support inheritance, while structs do not.

• Use classes for complex data structures, and structs for simple data types.