60+ Senior Sdet Engineer Interview Questions and Answers

Implement a data structure like a hash table or a cache to optimize memory search.

• Use a hash table to store the data with keys as memory locations

• Implement a cache to store frequently accessed data for faster retrieval

• Consider using indexing or sorting techniques to optimize search operations

Manual test cases for WhatsApp security features

• Verify end-to-end encryption is enabled for all messages

• Test two-factor authentication setup and login process

• Check for secure storage of user data on the device

• Test for secure transmission of media files

• Verify the effectiveness of blocking and reporting features

Reverse a string input without using any inbuilt method in Java

• Create a char array from the input string

• Use two pointers to swap characters from start and end of the array

• Continue swapping until the pointers meet in the middle

Write integration testcases for A-->B-->C microservices

• Test the communication between A and B microservices

• Test the data flow from B to C microservices

• Verify the response of C microservice based on input from A

• Check for error handling and edge cases in the integration flow

Yes, we can run tests locally without environment by using mock objects or stubs.

• Use mock objects or stubs to simulate the behavior of external dependencies

• Mocking frameworks like Mockito or Sinon can be used to create mock objects

• Avoid relying on external services or databases for local testing

Yes, Postman supports data driven testing through the use of variables and data files.

• Postman allows users to define variables and use them in requests for data driven testing.

• Data files such as CSV or JSON can be imported into Postman to drive test data.

• Iterations can be set up in Postman to run tests with different data sets.

Build testing is testing the software build to ensure it meets requirements. Shift left testing is moving testing earlier in the development process.

• Build testing involves testing the software build to ensure it meets functional and non-functional requirements

• Shift left testing is the practice of moving testing activities earlier in the software development process to catch defects sooner

• By shifting testing left, defects are identified and fixed earlier, reducing the cost and...read more

Cassandra is a distributed NoSQL database management system designed for handling large amounts of data across multiple servers.

• Cassandra is used for storing and managing large amounts of structured data across multiple commodity servers.

• It provides high availability and fault tolerance with no single point of failure.

• Cassandra is commonly used for real-time analytics, IoT data, messaging platforms, and more.

• It uses a decentralized architecture with a masterless design, allow...read more

Static variables and methods can be accessed using the class name directly.

• Use the class name followed by a dot operator to access static variables and methods.

• No instance of the class is required to access static members.

• Example: ClassName.staticVariableName or ClassName.staticMethodName()

Java program to print words by ascending count value

• Create a HashMap to store word frequencies

• Iterate through the array of strings and update the frequencies in the HashMap

• Use a TreeMap to sort the HashMap by values in ascending order

• Print the words in ascending count value order

To log latency for an API, you can use logging frameworks like Log4j or SLF4J to record timestamps before and after the API call.

• Use a logging framework like Log4j or SLF4J to record timestamps before and after the API call

• Calculate the latency by subtracting the timestamps

• Include the latency information in the log message for monitoring and analysis

To scroll a web element, use actions class to perform scroll actions

• Create an instance of Actions class

• Use moveToElement() method to move to the desired element

• Perform scroll actions using sendKeys(Keys.ARROW_DOWN) or sendKeys(Keys.PAGE_DOWN)

• Example: Actions actions = new Actions(driver); actions.moveToElement(element).sendKeys(Keys.ARROW_DOWN).perform();

Implicit wait is set globally for all elements, while explicit wait is applied only to specific elements.

• Implicit wait is set using driver.manage().timeouts().implicitlyWait() method

• Explicit wait is set using WebDriverWait class with ExpectedConditions

• Implicit wait is applied globally to all elements, while explicit wait is applied only to specific elements

• Implicit wait is used to wait for elements to load before performing actions, while explicit wait is used to wait for spe...read more

Java program to display unique characters in an array of strings

• Iterate through each string in the array

• Use a HashSet to keep track of unique characters

• For each character in the string, check if it is already in the HashSet and add it if not

BDD framework in test automation focuses on behavior-driven development principles to create automated tests.

• BDD framework uses natural language to define test scenarios

• Tests are written in a human-readable format using Given-When-Then syntax

• Tools like Cucumber and SpecFlow are commonly used for BDD test automation

POM stands for Page Object Model, a design pattern used in test automation to create reusable and maintainable code by separating test scripts from web elements.

• POM helps in creating a clear separation between test code and page-specific code

• Each web page is represented as a separate class in POM

• Page Objects contain the locators and methods to interact with the elements on that page

• POM promotes code reusability and maintainability in test automation

The best time to buy or sell stock depends on various factors such as market conditions, company performance, and personal financial goals.

• Consider buying stocks when the market is down and selling when it is up to maximize profits.

• Research the company's financial health, growth potential, and industry trends before making a decision.

• Set clear investment goals and risk tolerance to determine the best time to buy or sell stocks.

• Diversify your portfolio to reduce risk and prote...read more

A mean heap is a data structure that minimizes the cost of accessing the smallest element.

• Mean heap is a type of binary heap where the value of each node is less than or equal to the values of its children.

• It is useful for finding the minimum element quickly, as the root node always contains the smallest value.

• Insertion and deletion operations in a mean heap have a time complexity of O(log n).

A binary search tree (BST) is a data structure that organizes elements in a hierarchical manner, allowing for efficient searching, insertion, and deletion.

• BST is a type of binary tree where each node has at most two children.

• The left child of a node is always smaller than the node, and the right child is always greater.

• BST allows for efficient searching with a time complexity of O(log n) on average.

• Common operations on BST include insertion, deletion, and searching for a spec...read more

Private matter

• Personal

• Intimate

CORS issues occur when a web application tries to make a request to a different domain than the one it originated from.

• Enable CORS on the server by adding appropriate headers like Access-Control-Allow-Origin

• Use a proxy server to make requests on behalf of the client

• Ensure that the client-side code is making requests correctly with the appropriate headers

• Consider using JSONP as an alternative to CORS in some cases

To create a CI/CD job, you need to define the steps for building, testing, and deploying code automatically.

• Define the source code repository to pull code from

• Set up build steps to compile code and run tests

• Configure deployment steps to deploy code to target environments

• Integrate with version control system for triggering builds on code changes

• Use CI/CD tools like Jenkins, GitLab CI, or CircleCI

A library for API testing that provides a set of functions and utilities to simplify the testing process.

• The library should have functions to send HTTP requests and validate responses.

• It should support different authentication methods like OAuth, JWT, etc.

• The library should handle common API testing scenarios like testing CRUD operations, handling different HTTP methods, etc.

• It should provide utilities for data-driven testing, allowing testers to easily parameterize and itera...read more

Virtualization is the process of creating a virtual version of a device or resource, such as a server, storage device, network or operating system.

• Virtualization allows multiple virtual instances to run on a single physical machine

• It helps in optimizing resources and increasing efficiency

• Examples include VMware, VirtualBox, and Hyper-V

An automation framework is a set of guidelines, rules, and tools that help in creating automated tests for software applications.

• Automation frameworks provide structure and organization for automated testing

• They help in reducing the effort required to maintain and update automated tests

• Frameworks can include libraries, coding standards, and best practices for test automation

• Examples of automation frameworks include Selenium, TestNG, and Robot Framework

Python code to reverse an array of strings

• Use the built-in function 'reverse()' to reverse the array of strings

• Alternatively, you can use slicing to reverse each individual string in the array

Java program to split a string into an array of strings

• Use the split() method of the String class to split the string based on a delimiter

• Store the result in an array of strings

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

Data structure is a way of organizing and storing data in a computer so that it can be accessed and manipulated efficiently.

• Data structures define the way data is organized and stored in memory.

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

• Choosing the right data structure is crucial for efficient data manipulation and retrieval.

React is a JavaScript library for building user interfaces.

• React allows developers to create reusable UI components.

• It uses a virtual DOM for efficient updates.

• React is maintained by Facebook and a community of developers.

• JSX is a syntax extension used in React to write HTML-like code within JavaScript.

Kafka is a distributed streaming platform used for building real-time data pipelines and streaming applications.

• Kafka is designed to handle high-throughput, fault-tolerant, and scalable real-time data streams.

• It allows for the publishing and subscribing to streams of records, similar to a message queue.

• Kafka is often used for log aggregation, stream processing, event sourcing, and real-time analytics.

• It provides features such as fault tolerance, replication, and partitioning ...read more

Handle bugs by identifying, prioritizing, fixing, and testing them to ensure quality software.

• Identify bugs by reproducing them and analyzing logs

• Prioritize bugs based on impact and severity

• Fix bugs by writing code changes and performing code reviews

• Test fixes to ensure they resolve the issue without introducing new bugs

As a Senior SDET Engineer, my role in the company is to design, develop, and maintain automated testing frameworks to ensure the quality of software products.

• Designing and implementing automated testing frameworks

• Developing test scripts and scenarios

• Collaborating with developers and QA teams to identify and fix software defects

• Participating in code reviews and providing feedback on testability

• Analyzing test results and providing recommendations for improvements

String reverse is the process of reversing the order of characters in a string.

• Create a new string and iterate through the original string in reverse order, appending each character to the new string.

• Use built-in functions like reverse() in some programming languages to reverse the string directly.

• Implement a custom algorithm to swap characters from the beginning and end of the string until reaching the middle.

Count the occurrences of '-/1' in a given array of strings.

• Iterate through the array and count the number of times '-/1' appears in each string.

• Use a loop to go through each element of the array and check for the substring '-/1'.

• Keep a counter to track the total occurrences of '-/1' in the array.

Method hiding is a concept in object-oriented programming where a subclass defines a method with the same name as a method in its superclass, effectively hiding the superclass method.

• Method hiding allows a subclass to provide its own implementation of a method without overriding the superclass method.

• The subclass method must have the same signature (name and parameters) as the superclass method to hide it.

• To access the superclass method from the subclass, you can use the 'sup...read more

Selenium waits are used to make the test scripts wait for a certain condition to be met before proceeding.

• Selenium waits help in handling dynamic web elements that load at different times.

• There are three types of waits in Selenium: Implicit wait, Explicit wait, and Fluent wait.

• Implicit wait sets a default waiting time for the entire script.

• Explicit wait waits for a specific condition to be met before proceeding.

• Fluent wait is used to define maximum wait time for a particular ...read more

Polymorphism is the ability of a function or method to behave differently based on the object it is acting upon.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: Animal class with methods eat() and sleep(). Dog and Cat classes can override these methods to have their own behavior.

Search for a specific string in an array of strings.

• Iterate through the array and compare each string with the target string.

• Use a loop to go through each element in the array and check for a match.

• Consider using built-in methods like indexOf() or includes() for efficient searching.

• Handle cases where the target string is not found in the array.

Use stack data structure to check for balanced parentheses in a string.

• Create an empty stack to store opening parentheses

• Iterate through the string and push opening parentheses onto the stack

• When encountering a closing parenthesis, pop from the stack and check if it matches the corresponding opening parenthesis

• If stack is empty at the end and all parentheses have been matched, the string is balanced

Find all subarrays in a given array of strings

• Iterate through the array and consider each element as the starting point of a subarray

• For each starting point, iterate through the array to find all possible subarrays

• Store each subarray found in a separate list

A testbed is a platform or environment used for testing software applications or hardware components.

• Testbeds can simulate real-world scenarios to test the functionality and performance of software or hardware.

• They can include a combination of hardware, software, and network configurations.

• Testbeds are used to identify bugs, performance issues, and compatibility problems before releasing a product.

• Examples of testbeds include virtual machines, physical devices, and cloud-base...read more

Factory pattern is a creational design pattern that provides an interface for creating objects in a superclass, but allows subclasses to alter the type of objects that will be created.

• Create an interface or abstract class to define the factory method

• Create concrete classes that implement the interface or extend the abstract class

• Factory class should have a method that returns an object of the interface type based on input parameters

Find the maximum sum of a contiguous subarray within an array of integers.

• Use Kadane's algorithm to find the maximum subarray sum efficiently.

• Initialize two variables - maxEndingHere and maxSoFar.

• Iterate through the array and update the variables accordingly.

• Example: Input [1, -2, 3, 4, -1, 2, 1, -5, 4], Output: 10 (subarray [3, 4, -1, 2, 1])

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

• HashMap is part of the Java Collections framework.

• It uses hashing to store and retrieve elements quickly.

• Each key in a HashMap must be unique.

• HashMap allows for null keys and values.

• Example: HashMap map = new HashMap<>();

The question seems to be incomplete or garbled, please provide more context or clarification.

• Ask for clarification or more context from the interviewer

• Confirm if the question was stated correctly

• Provide a response based on the information provided

Pattern search problem

• The problem involves searching for a specific pattern in an array of strings

• The pattern can be a substring or a regular expression

• The solution should return the indices or strings that match the pattern

A binary tree is a hierarchical data structure in which each node has at most two children.

• Consists of nodes connected by edges

• Each node can have at most two children

• The left child is smaller than the parent, and the right child is greater

• Used for efficient searching, sorting, and organizing data