700+ Senior Software Developer Interview Questions and Answers

Lambda expressions in Java 8 are used to provide a concise way to represent a single method interface.

• Lambda expressions are used to provide implementation of functional interfaces.

• They enable you to treat functionality as a method argument, or code as data.

• Syntax of lambda expressions is (argument) -> (body).

• Example: (int a, int b) -> a + b

ETL process involves extracting data from various sources, transforming it to fit the data warehouse schema, and loading it into the warehouse.

• Extract: Data is extracted from different sources such as databases, files, APIs, etc.

• Transform: Data is cleaned, filtered, aggregated, and transformed to match the data warehouse schema.

• Load: Transformed data is loaded into the data warehouse for analysis and reporting.

• Example: Extracting sales data from a CRM system, transforming it ...read more

I approach problem-solving in software development by breaking down the issue, researching possible solutions, and collaborating with team members.

• Identify the problem and gather all relevant information

• Break down the problem into smaller, manageable tasks

• Research possible solutions and consider different approaches

• Collaborate with team members to brainstorm ideas and gather feedback

• Implement and test the solution, making adjustments as needed

The question asks to find the similarity between two words by developing our own sense of similarity.

• Normalize the length of the Longest Common Subsequence (LCS) by dividing it by the total length of the string.

• Implement a function that calculates the LCS between two words.

• Divide the length of the LCS by the sum of the lengths of the two words.

• Return the normalized similarity score as the result.

MVC components include Model (data), View (UI), and Controller (logic) for organizing code in a software application.

• Model: Represents data and business logic, interacts with the database. Example: User model storing user information.

• View: Represents the UI, displays data to the user. Example: HTML/CSS templates for displaying user profile.

• Controller: Handles user input, updates the model, and selects the view to display. Example: User controller handling user registration.

A hash map in Java is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values based on keys.

• Hash map uses an array to store key-value pairs.

• Keys are hashed to determine the index where the value will be stored.

• Collision resolution techniques like chaining or open addressing are used to handle hash collisions.

• Example: HashMap<String, Integer> map = new HashMap<>(); map.put("key", 123); int value = map.get("key");

Checking if a string is not null without using string != null.

• Use string.IsNullOrEmpty() method

• Use string.IsNullOrWhiteSpace() method

• Use string.Compare() method to compare with an empty string

• Use string.Length property to check if length is greater than 0

Intermediate operations return a new stream and allow further operations, while terminal operations produce a result or side-effect.

• Intermediate operations include filter(), map(), sorted(), etc.

• Terminal operations include forEach(), collect(), reduce(), etc.

• Intermediate operations are lazy and only executed when a terminal operation is called.

• Terminal operations are eager and trigger the stream to process the data.

PUT is used to update or replace an existing resource, while POST is used to create a new resource.

• PUT is idempotent, meaning multiple identical requests will have the same effect as a single request

• POST is not idempotent, meaning multiple identical requests may have different effects

• PUT requests are used to update an existing resource with a new representation, while POST requests are used to create a new resource

• PUT requests are typically used for updating specific fields o...read more

The upcoming projects will utilize a combination of technologies including Java, Python, and React.

• Java

• Python

• React

Yes, I am familiar with software testing methodologies and tools.

• I have experience with both manual and automated testing

• I am familiar with Agile testing methodologies such as Scrum and Kanban

• I have used tools like Selenium, JUnit, and TestNG for testing

• I understand the importance of regression testing and performance testing

Scalability in software architecture refers to the ability of a system to handle increasing amounts of work or its potential to accommodate growth.

• Scalability involves designing a system in a way that allows it to easily expand in terms of processing power, storage capacity, or network bandwidth.

• Horizontal scalability involves adding more machines to distribute the load, while vertical scalability involves upgrading existing resources.

• Examples of scalable architectures includ...read more

Yes, I have extensive experience with version control systems like Git.

• I have been using Git for version control in all my projects for the past 5 years.

• I am proficient in creating branches, merging code, resolving conflicts, and performing code reviews using Git.

• I have experience with popular Git hosting services like GitHub, GitLab, and Bitbucket.

Yes, I have experience in both backend and frontend development.

• I have worked on backend development using languages like Java, Python, and Node.js to build APIs and handle server-side logic.

• I have experience in frontend development using technologies like HTML, CSS, and JavaScript to create user interfaces and interactive web applications.

• I have used frameworks like React and Angular for frontend development and frameworks like Spring and Express for backend development.

Yes, I have worked with several frameworks and libraries including React, Angular, and Node.js.

• Worked with React for building user interfaces

• Experience with Angular for front-end development

• Utilized Node.js for server-side scripting

A state in React is a JavaScript object that stores data relevant to a component and can be updated over time.

• State is initialized in a component's constructor using this.state = {}

• State can be updated using this.setState() method

• State changes trigger re-rendering of the component

INNER JOIN returns rows when there is at least one match in both tables, while OUTER JOIN returns all rows from both tables.

• INNER JOIN only returns rows that have matching values in both tables

• OUTER JOIN returns all rows from both tables, filling in NULLs for unmatched rows

• Types of OUTER JOIN include LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id

• Example: SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.i...read more

MVC architecture separates concerns, improves code organization, promotes reusability, and enhances maintainability.

• Separates concerns: MVC separates the application into three main components - Model, View, and Controller, allowing for easier management of code and logic.

• Improves code organization: Each component in MVC has a specific role, making it easier to organize and maintain code.

• Promotes reusability: With clear separation of concerns, components can be reused in diff...read more

RANK() assigns a unique rank to each row based on the specified column, while ROW_NUMBER() assigns a unique sequential row number to each row.

• RANK() may have gaps in the ranking if there are ties, while ROW_NUMBER() will not have any gaps.

• RANK() will assign the same rank to rows with the same value, while ROW_NUMBER() will assign a unique row number to each row.

• ROW_NUMBER() is used to generate a unique sequential number for each row in a result set, while RANK() is used to as...read more

Slice is a method that extracts a portion of an array without modifying the original array, while splice is a method that adds or removes elements from an array.

• Slice returns a shallow copy of a portion of an array based on start and end index parameters.

• Splice can add new elements to an array or remove existing elements by specifying the start index and number of elements to remove.

• Example: const arr = [1, 2, 3, 4, 5]; arr.slice(1, 3) will return [2, 3], while arr.splice(1, ...read more

Skip, SkipWhile, and SkipLast are LINQ methods used to skip elements in a sequence.

• Skip(n) skips the first n elements in a sequence.

• SkipWhile(predicate) skips elements in a sequence while the predicate is true.

• SkipLast(n) skips the last n elements in a sequence.

• LINQ is a language integrated query that allows querying data from different data sources.

• SQL is a database management system that uses Structured Query Language to manage data.

• LINQ is used to query data from different...read more

To find the individual with a different weight among nine, only three weighings are needed using a balance scale.

• First Weighing: Divide the nine individuals into three groups of three and weigh two groups against each other.

• Second Weighing: Depending on the result, take the group that was heavier or lighter and divide it into three individuals, weighing two of them.

• Third Weighing: If the second weighing is equal, the third individual is the one with the different weight; if n...read more

4

• Extensive experience in software development

• Strong knowledge of programming languages and frameworks

• Proficient in problem-solving and debugging

• Ability to design and implement complex software systems

Threading is a way for a program to execute multiple tasks concurrently. Different scheduling algorithms determine the order in which threads are executed.

• Threading allows multiple tasks to run concurrently within a single process.

• Scheduling algorithms determine the order in which threads are executed, such as First-Come-First-Served (FCFS), Round Robin, Priority-Based Scheduling, etc.

• FCFS schedules threads based on their arrival time, Round Robin assigns a fixed time slice t...read more

N+1 SELECT problem in Hibernate occurs when a query results in N+1 database queries being executed instead of just one.

• Occurs when a query fetches a collection of entities and then for each entity, another query is executed to fetch related entities individually

• Can be resolved by using fetch joins or batch fetching to fetch all related entities in a single query

• Example: Fetching a list of orders and then for each order, fetching the customer details separately

SOLID principles are a set of five design principles in object-oriented programming to make software designs more understandable, flexible, and maintainable.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the func...read more

Find maximum for each contiguous subarray of size k from an array of size n.

• Iterate through the array and keep track of maximum for each subarray of size k

• Use a sliding window approach to efficiently calculate maximum for each subarray

• Time complexity: O(n)

• Example: arr = [10, 5, 2, 7, 1, 9, 4], k = 3, output = [10, 7, 7, 9, 9]