100+ Senior Software Engineer 2 Interview Questions and Answers

Implement a Smoke Collector problem

• Create a class SmokeCollector with methods to collect smoke data

• Implement a method to start collecting smoke data

• Design a method to analyze and store the collected smoke data

Auto scaling of EC2 instances involves setting up policies to automatically adjust the number of instances based on demand.

• Set up CloudWatch alarms to monitor metrics like CPU utilization or network traffic

• Create an Auto Scaling Group with desired minimum and maximum number of instances

• Define scaling policies to add or remove instances based on the alarms triggered

• Test the auto scaling by simulating load on the instances

To write a procedure in PL/1, use the PROC statement followed by the procedure name and the necessary code.

• Begin with the PROC statement followed by the procedure name

• Add the necessary code within the procedure

• End the procedure with the END statement

• Example: PROC MYPROC; /* code here */ END MYPROC;

InjectMocks is used to inject mocks into a test class, while MockBean is used to mock Spring beans in a Spring context.

• InjectMocks is a Mockito annotation used to inject mock objects into a test class.

• MockBean is a Spring Boot annotation used to mock Spring beans in a Spring context.

• InjectMocks is used in standalone tests, while MockBean is used in integration tests.

• Example: @InjectMocks private UserService userService;

• Example: @MockBean private UserRepository userRepository;

Login components in Angular handle user authentication and authorization.

• Use Angular's built-in forms module to create login form

• Implement authentication service to handle login logic

• Use Angular router to navigate to different pages based on login status

Use SQL query with WHERE clause to delete rows older than 6 months from current date

• Use CURRENT_DATE() function to get current date

• Use DATE_SUB() function to subtract 6 months from current date

• Write a DELETE query with WHERE clause to delete rows older than calculated date

Security options for application and advantages/disadvantages of AWS EC2

• Security options for application include encryption, access control, firewalls, and regular security audits

• AWS EC2 advantages include scalability, flexibility, and cost-effectiveness

• AWS EC2 disadvantages include potential security vulnerabilities, complexity in managing instances, and potential downtime

Garbage collector is a mechanism in programming languages that automatically frees up memory occupied by objects that are no longer in use.

• Garbage collector is responsible for managing memory in a program.

• It identifies and frees up memory occupied by objects that are no longer needed.

• Garbage collector uses various algorithms to determine which objects are eligible for garbage collection.

• Common garbage collection algorithms include reference counting, mark and sweep, and gener...read more

BookMyShow is an online platform for booking movie tickets and events. Here's the architecture design.

• The architecture should be scalable and flexible to handle high traffic during peak hours.

• The system should have multiple layers including presentation, application, and data storage.

• Use microservices architecture to break down the system into smaller, independent services.

• Implement caching mechanisms to improve performance and reduce load on the database.

• Use load balancers t...read more

To debug S02 error in Mainframe, analyze the error message, check system logs, review program logic, and use debugging tools.

• Analyze the error message to understand the root cause of the S02 error.

• Check system logs for any additional information related to the error.

• Review the program logic to identify any potential issues that could lead to the S02 error.

• Use debugging tools like IBM Debug Tool or Xpediter to step through the code and pinpoint the exact location of the error.

Program to find the sequence order of a number

• Create an array to store the sequence order

• Iterate through the numbers from 1 to the given number

• Check if each number is divisible by the given number

• If divisible, add it to the sequence order array

• Return the sequence order array

I used the Service Registry design pattern in my microservice.

• Service Registry pattern is used to dynamically register and discover services in a distributed system.

• It helps in decoupling service consumers from service providers.

• Examples of Service Registry tools include Netflix Eureka and Consul.

Event loop is a mechanism in JavaScript that allows for asynchronous programming by handling and executing tasks in a non-blocking manner.

• Event loop is responsible for managing the execution of code in JavaScript.

• It continuously checks for tasks in the event queue and executes them one by one.

• Tasks can be added to the event queue through various mechanisms like timers, user interactions, or network requests.

• The event loop ensures that the JavaScript runtime remains responsive...read more

Implement k-Vendor problem

• Create a function that takes in an array of strings and an integer k

• Return the kth most frequent string in the array

• Use a hashmap to store the frequency of each string

Our current project architecture follows a microservices design pattern with Docker containers and Kubernetes for orchestration.

• Microservices architecture

• Docker containers

• Kubernetes for orchestration

Code to add 2 numbers using functional interface

• Create a functional interface with a method to add two numbers

• Implement the functional interface using a lambda expression

• Call the method to add two numbers

Design a ticket booking system like BookMyShow

• Use a database to store movie details, show timings, and seat availability

• Implement user authentication and authorization for booking tickets

• Include a payment gateway for secure transactions

• Design a user-friendly interface for browsing and booking tickets

• Allow users to rate and review movies after watching them

Sort 3 arrays and find the closest numbers between them

• Sort each array in ascending order

• Iterate through each array and compare the absolute difference between each element

• Keep track of the smallest difference found so far

• Return the pair of numbers with the smallest difference

To address a full /boot partition, remove unnecessary files, uninstall old kernels, and increase partition size if needed.

• Delete unnecessary files in /boot directory

• Uninstall old kernels to free up space

• Increase the size of the /boot partition if necessary

The standard for authentications is a set of guidelines and protocols used to verify the identity of users accessing a system.

• Authentication standards ensure secure access to systems and protect against unauthorized access.

• Common authentication standards include OAuth, OpenID Connect, and SAML.

• Authentication factors can include passwords, biometrics, and two-factor authentication.

• Authentication protocols like HTTPS and SSL/TLS provide secure communication channels.

• Multi-facto...read more

Jenkins is a popular open-source automation server used for continuous integration and continuous delivery (CI/CD) pipelines.

• Jenkins is used to automate the building, testing, and deployment of software projects.

• CI/CD pipelines in Jenkins help in automating the software delivery process by integrating code changes frequently and delivering them to production.

• Jenkins allows for the creation of pipelines that define the steps to be executed, such as compiling code, running test...read more

Stacks and heaps are data structures used to store and manage memory. Sorting techniques are algorithms used to sort data.

• Stacks are a LIFO (last in, first out) data structure. Examples include the call stack in programming and undo/redo functionality in text editors.

• Heaps are a dynamic memory allocation technique. Examples include the heap memory in programming and the memory allocation in operating systems.

• Sorting techniques include bubble sort, insertion sort, selection so...read more

Design a Common Billing System for Azure services.

• Utilize Azure Billing API to track usage and costs

• Implement role-based access control for billing information

• Include automated invoicing and payment processing

• Integrate with Azure Active Directory for user authentication

• Provide detailed billing reports and analytics for customers

Microservice architecture is an architectural style that structures an application as a collection of loosely coupled services.

• Each service is self-contained and can be developed, deployed, and scaled independently.

• Services communicate with each other over lightweight protocols like HTTP or messaging queues.

• Microservices allow for better scalability, flexibility, and resilience compared to monolithic architectures.

• Examples of companies using microservices include Netflix, Ama...read more

MVC routing and filters in .NET

• Routing maps URLs to controller actions

• Filters are used to add pre/post processing logic to controller actions

• Filters can be applied globally or to specific actions/controllers

• Examples of filters include authorization, caching, and exception handling

Apache Kafka is a distributed streaming platform that allows for the publishing and subscribing to streams of records.

• Apache Kafka is designed to be highly scalable and fault-tolerant.

• It uses a distributed commit log to store messages.

• Producers publish messages to topics, and consumers subscribe to topics to receive messages.

• Kafka can be used for real-time stream processing, data pipelines, and event sourcing.

• It provides strong durability guarantees and high throughput.

Use a scheduled job to delete data older than 90 days from the database.

• Create a scheduled job that runs daily to check for data older than 90 days

• Use a query to select and delete data older than 90 days

• Test the job to ensure it is working correctly

Circuit breaker pattern is a design pattern used in software development to prevent cascading failures in distributed systems.

• It is used to handle faults and failures in a distributed system by temporarily blocking requests to a failing service.

• When the circuit breaker detects that the service is healthy again, it allows requests to flow through.

• It helps in improving the resilience and fault tolerance of the system.

• Example: Netflix's Hystrix library implements the circuit bre...read more

Design a high level system for the assignment

• Identify the main components of the system such as user interface, backend server, database, etc.

• Define the interactions between the components and how data flows through the system

• Consider scalability, reliability, and security aspects in the design

• Use appropriate technologies and frameworks to implement the system

• Ensure proper documentation and testing procedures are in place

Program to find smallest element in an array of strings

• Iterate through the array and compare each element to find the smallest one

• Use a variable to keep track of the smallest element found so far

• Return the smallest element at the end

APIPA address in Windows Server is a self-assigned IP address when DHCP server is not available.

• APIPA stands for Automatic Private IP Addressing

• It is a feature in Windows that automatically assigns an IP address in the range of 169.254.0.1 to 169.254.255.254 when a DHCP server is not available

• APIPA is used to ensure that a device can still communicate on a network even if a DHCP server is not present

DNS in Linux environment is a system that translates domain names to IP addresses.

• DNS stands for Domain Name System

• It is responsible for translating human-readable domain names (like google.com) into IP addresses (like 172.217.7.238)

• DNS servers store DNS records which contain information about domain names and their corresponding IP addresses

• Linux systems use DNS to resolve domain names to IP addresses when connecting to the internet

Program to sort an array of strings in ascending order

• Use a sorting algorithm like bubble sort, selection sort, or merge sort

• Compare adjacent elements and swap them if they are in the wrong order

• Repeat this process until the array is sorted

Use list comprehension to add corresponding elements of two arrays.

• Use list comprehension to iterate over both arrays simultaneously and add corresponding elements.

• Ensure both arrays are of the same length.

• Example: result = [str(int(x) + int(y)) for x, y in zip(array1, array2)]

Docker allows for easy and efficient containerization of applications, leading to improved scalability, portability, and resource utilization.

• Improved scalability: Docker containers can be easily scaled up or down based on demand, allowing for efficient resource allocation.

• Portability: Docker containers can run on any system that supports Docker, making it easy to deploy applications across different environments.

• Resource utilization: Docker's lightweight nature and efficient...read more

Springboot can be implemented using any IDE that supports Java development.

• Spring Tool Suite (STS) is a popular IDE for Springboot development

• IntelliJ IDEA also has good support for Springboot

• Eclipse with Spring Tooling plugin can also be used

• IDEs provide features like auto-completion, debugging, and deployment

• Maven or Gradle can be used as build tools for Springboot projects

Set up a ci/cd pipeline for automated software deployment

• Choose a CI/CD tool like Jenkins, GitLab CI, or CircleCI

• Define the stages of the pipeline (build, test, deploy)

• Integrate with version control system (e.g. GitHub, Bitbucket)

• Automate testing and code quality checks

• Configure notifications for pipeline status updates

Design a Movie Theater ticket booking system

• Create a database to store movie information, showtimes, and seat availability

• Develop a user-friendly interface for customers to browse movies, select showtimes, and choose seats

• Implement a payment system for customers to purchase tickets online

• Include features like seat selection, seat reservation, and ticket confirmation

Design a chess platform for tournaments

• Implement user registration and login functionality

• Allow users to create or join tournaments

• Include features for pairing players, tracking scores, and generating leaderboards

• Provide options for different tournament formats such as round-robin or knockout

• Include a feature for spectators to watch ongoing games

• Implement a time control system for games

• Allow for customization of tournament settings such as time limits and piece sets

An online real time document sharing tool for collaboration and communication

• Implement real-time editing and commenting features

• Allow multiple users to access and edit the document simultaneously

• Provide version control and history tracking

• Include user authentication and permission settings

• Support various file formats such as text, images, and videos

APIGEE is an API management platform that enables businesses to design, secure, deploy, and scale APIs. Kafka is a distributed streaming platform for building real-time data pipelines and streaming applications.

• APIGEE helps businesses manage their APIs by providing tools for design, security, deployment, and scalability.

• Kafka is used for building real-time data pipelines and streaming applications by enabling high-throughput, fault-tolerant, and scalable messaging.

• APIGEE can ...read more

Docker is a platform for developing, shipping, and running applications in containers, which are lightweight, portable, and isolated environments.

• Docker is a tool that allows you to package an application and its dependencies into a standardized unit called a container.

• Containers are isolated environments that contain everything needed to run the application, including code, runtime, system tools, libraries, and settings.

• Containerization helps in ensuring consistency across d...read more

The split function in Java is used to split a string into an array of substrings based on a specified delimiter.

• The split function takes a regular expression as a parameter to specify the delimiter.

• The result is an array of strings containing the substrings.

• Example: String str = 'Hello,World'; String[] parts = str.split(','); // parts = ['Hello', 'World']

Peak and majority element finding algorithms

• Peak element: binary search for element greater than both neighbors

• Majority element: Boyer-Moore voting algorithm

• Boyer-Moore: iterate through array, count occurrences of each element, return element with count > n/2

Scaling the API involves optimizing performance, increasing capacity, and ensuring reliability.

• Implementing caching mechanisms to reduce server load and improve response times

• Using load balancers to distribute incoming traffic evenly across multiple servers

• Optimizing database queries and indexes to handle increased data volume

• Implementing horizontal scaling by adding more servers to handle increased traffic

• Monitoring performance metrics and scaling resources dynamically based...read more

HashMap in Java 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 linked lists.

• It uses the hashCode() method of keys to determine the index where the value will be stored.

• If two keys have the same hashCode, they are stored in the same linked list at that index.

• HashMap allows null keys and values, but only one null key.

• Example: HashMap<String, Integer> map = new Has...read more

Rate limiter for an API to control the number of requests per unit of time.

• Use a sliding window algorithm to track the number of requests within a specific time frame.

• Implement a token bucket algorithm to limit the number of requests that can be made.

• Consider using a distributed cache like Redis to store and manage request limits.

• Return appropriate HTTP status codes (e.g. 429 - Too Many Requests) when the limit is exceeded.