90+ Sdet Lead Interview Questions and Answers

The candidate was asked various questions related to software development and testing.

• To write a palindrome program without using any in-built method, the candidate can use a loop to compare characters from both ends of the string.

• To approach and run only 50 out of 500 test cases, the candidate can prioritize the test cases based on criticality and execute the most important ones first.

• The framework used in the candidate's project was not mentioned.

• To handle a team member's a...read more

Answers to interview questions for Sdet Lead position

• 1. FluentWait syntax: FluentWait<WebDriver> wait = new FluentWait<>(driver)

• 2. To scroll to the bottom of the page in Selenium, you can use JavaScriptExecutor or Actions class

• 3. Syntax for Implicit Wait: driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS)

• Implicit Wait is not part of Overloading or Overriding

• 4. JavaScriptExecutor is an interface in Selenium that allows executing JavaScript code in the context of ...read more

Reverse the whole string with spaces remaining in the same place

• Iterate through the string and reverse each word individually

• Keep track of spaces and add them back in the reversed string

• Join the reversed words together to form the final reversed string

Work-life balance impacts employee satisfaction, which can influence salary and benefits in a payment package.

• Higher salaries may compensate for demanding work hours, e.g., tech companies offering bonuses for overtime.

• Flexible work arrangements can be a part of the payment package, e.g., remote work options.

• Companies with better work-life balance often attract talent, leading to competitive salaries.

• Benefits like extra vacation days can enhance work-life balance, reflecting i...read more

Bubble sorting has a time complexity of O(n^2) for a sorted list.

• Bubble sorting has a worst-case time complexity of O(n^2) for a sorted list.

• The time complexity does not change even if the list is already sorted.

• Example: If we have a sorted list of size n, bubble sorting will still take O(n^2) time.

Java program to remove duplicates from an array without using Set.

• Use a nested loop to compare each element with others.

• Create a new array to store unique elements.

• Example: For arr={2,2,3,3}, output should be {2,3}.

• Ensure to check if an element is already in the new array before adding.

OOPs is Object-Oriented Programming, CSS is Cascading Style Sheets, HTML is Hypertext Markup Language. Batch processing is a method of processing data in groups.

• OOPs 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.

• CSS is used for styling web pages and controlling their layout. It stands for Cascading Style Sheets.

• HTML is the standard markup language for creating web pages. It stands for...read more

The median of two sorted arrays can be found in O(log n) time using binary search.

• Divide the arrays into two parts at a certain index and compare the medians of both parts.

• Adjust the dividing index based on the comparison until the medians are equal or adjacent.

• Handle edge cases like uneven array lengths and one array being entirely smaller than the other.

Event loop is a mechanism that allows for asynchronous programming by handling and executing events in a loop.

• Event loop is a part of the runtime environment that continuously checks the event queue and executes the callback functions associated with the events.

• It helps in managing non-blocking I/O operations efficiently by allowing the program to continue running while waiting for I/O operations to complete.

• Event loop is commonly used in JavaScript for handling asynchronous ...read more

Python program to hit get call and fetch required details.

• Use the requests library to make a GET request to the desired URL

• Extract the required details from the response using JSON parsing or other methods

• Handle any errors or exceptions that may occur during the process

Database warehousing is the process of collecting, storing, and managing data from various sources for analysis and reporting.

• Database warehousing involves extracting data from different sources

• Data is transformed and loaded into a central repository for analysis

• It allows for complex queries and reporting on large datasets

• Examples include data warehouses like Amazon Redshift, Google BigQuery

Disjoint set union method is a data structure used to efficiently merge two sets and find the parent set of an element in a graph.

• Disjoint set union method is also known as Union-Find data structure.

• It consists of two main operations: union (merge two sets) and find (determine the parent set of an element).

• Path compression and union by rank are common optimizations used in disjoint set union method.

• Example: In a graph with nodes representing cities, disjoint set union can be ...read more

React is a JavaScript library for building user interfaces, while Vue.js is a progressive JavaScript framework for building web interfaces.

• React is a library, while Vue.js is a framework

• React uses a virtual DOM for better performance, while Vue.js uses a virtual DOM as well but with a different approach

• React has a larger community and ecosystem compared to Vue.js

• React is more flexible and allows for more customization, while Vue.js is easier to learn and use for beginners

Trees are data structures that consist of nodes connected by edges, with a root node at the top. Balanced trees are trees where the heights of subtrees differ by at most one.

• Trees are hierarchical data structures with a root node and child nodes.

• Balanced trees are trees where the heights of subtrees differ by at most one, ensuring efficient search and insertion operations.

• Examples of balanced trees include AVL trees, red-black trees, and B-trees.

Program to compare elements between two arrays of strings.

• Iterate through each element in both arrays and compare them one by one.

• Use a loop to compare elements at corresponding indexes in both arrays.

• Return true if all elements match, false otherwise.

LeetCode problems are great for practicing coding skills and preparing for technical interviews.

• LeetCode offers a variety of problems, from easy to hard, covering different data structures and algorithms.

• Practicing on LeetCode helps improve problem-solving skills and coding efficiency.

• Example problems include 'Two Sum' for arrays and 'Longest Substring Without Repeating Characters' for strings.

• Regular practice can help identify patterns in problems, making it easier to tackle...read more

Design a central logging system for efficient monitoring and troubleshooting.

• Use a centralized server to collect logs from all systems

• Implement log aggregation tools like ELK stack or Splunk

• Set up alerts for critical errors or anomalies

• Ensure secure access controls for log data

• Consider scalability and storage requirements

Debugging an application involves identifying and fixing issues in the code, while writing test cases ensures the application functions correctly.

• Understand the functionality of the application and identify the root cause of the issue

• Use debugging tools like breakpoints, logging, and stack traces to pinpoint the problem

• Write test cases to cover different scenarios and ensure the issue is resolved

• Reproduce the issue to validate the fix and prevent regression

• Document the debugg...read more

Visible nodes in a binary tree are the nodes that are not blocked by any other nodes when viewed from below.

• Traverse the binary tree level by level and keep track of the maximum value seen at each level. Any node with a value greater than the maximum value seen so far is considered a visible node.

• Example: For a binary tree with values [5, 3, 8, 1, 4, 7, 9], the visible nodes from below would be [5, 8, 9].

An abstract class is a class that cannot be instantiated and may contain abstract methods that must be implemented by its subclasses.

• Cannot be instantiated directly

• May contain abstract methods

• Used as a blueprint for other classes

Architectural design patterns are reusable solutions to common problems encountered in software design.

• Architectural design patterns provide guidelines on how to structure and organize software systems.

• Examples include MVC (Model-View-Controller), MVVM (Model-View-ViewModel), and Layered Architecture.

• They help improve the scalability, maintainability, and flexibility of software applications.

To find the shortest distance between two nodes, we can use algorithms like Dijkstra's or A*.

• Use Dijkstra's algorithm to find the shortest path between two nodes in a graph

• Implement A* algorithm for finding the shortest path in a grid-based environment

• Consider using Floyd-Warshall algorithm for finding all pairs shortest paths in a graph

QuickSort is one of the best sorting algorithms with an average time complexity of O(n log n).

• QuickSort is a divide and conquer algorithm that works by selecting a 'pivot' element and partitioning the array around the pivot.

• It has an average time complexity of O(n log n) and a worst-case time complexity of O(n^2).

• Example: ['apple', 'banana', 'cherry', 'date', 'fig'] can be sorted using QuickSort.

• Example: ['3', '1', '4', '1', '5', '9', '2', '6', '5'] can be sorted using QuickS...read more

BTEE stands for Breadth-First Tree Enumeration and it is a method used to traverse a tree data structure.

• BTEE is a technique used to visit all the nodes of a tree level by level, starting from the root node.

• It uses a queue data structure to keep track of the nodes to be visited next.

• BTEE ensures that all nodes at the same level are visited before moving on to the next level.

Testing a lift system involves multiple steps to ensure its functionality and safety.

• 1. Verify the lift system's basic functionality such as going up and down smoothly.

• 2. Test emergency stop functionality to ensure safety measures are in place.

• 3. Check for proper alignment of doors and sensors to prevent accidents.

• 4. Conduct load testing to ensure the lift can handle its maximum capacity.

• 5. Test communication systems between the lift and control panel for seamless operation.

Reverse the kth node in a linked list

• Traverse the linked list to find the kth node

• Reverse the kth node by changing its next pointer to point to the previous node

• Update the pointers of the previous and next nodes accordingly

• Handle edge cases such as k being out of bounds or kth node being the head of the list

Method overriding is a feature in object-oriented programming where a subclass provides a specific implementation of a method that is already provided by its superclass.

• In method overriding, the method in the subclass has the same name, return type, and parameters as the method in the superclass.

• The method in the subclass must have the same or wider access modifier than the method in the superclass.

• Method overriding allows for polymorphism, where a subclass object can be trea...read more