4500+ Senior Software Engineer Interview Questions and Answers

CTE, Temp table and Table variable are used to store temporary data in SQL Server.

• CTE (Common Table Expression) is a temporary named result set that can be referenced within a SELECT, INSERT, UPDATE, or DELETE statement.

• Temp table is a physical table that is created in the tempdb database and can be used to store temporary data.

• Table variable is a variable that can store a result set for later use and is similar to a temp table but is stored in memory.

• CTE is useful for recurs...read more

Array is a fixed-size data structure while ArrayList is a dynamic-size data structure in Java.

• Array has a fixed length, while ArrayList can dynamically resize.

• Array can store both primitive and object types, while ArrayList can only store object types.

• Array uses square brackets [] for declaration, while ArrayList uses angle brackets <>.

• Array is more memory efficient than ArrayList.

• Array provides direct access to elements using index, while ArrayList requires methods like get(...read more

Declare expression is used to define reusable expressions. Sub report is a report within a report.

• Declare expression helps in reducing redundancy and improving maintainability of the code.

• It allows defining expressions that can be used across multiple rules and decision tables.

• For example, a declare expression can be used to calculate the age of a customer based on their date of birth.

• A sub report is a report that is embedded within another report.

• It is used to display relate...read more

Microservices communicate with each other through APIs, message queues, or event-driven architecture.

• APIs: Microservices can communicate with each other through RESTful APIs or GraphQL.

• Message queues: Services can use message brokers like RabbitMQ or Kafka to send and receive messages.

• Event-driven architecture: Services can publish events to a message broker and subscribe to events they are interested in.

• Service discovery: Services can use tools like Consul or Eureka to disco...read more

Find the maximum profit from buying and selling a stock given an array of its values.

• Iterate through the array and keep track of the minimum value seen so far.

• Calculate the profit at each index and update the maximum profit seen.

• Return the maximum profit.

Yes

• I have extensive experience dealing with customers through email

• I prioritize clear and concise communication to address customer inquiries and concerns

• I ensure prompt responses and follow-ups to maintain customer satisfaction

• I have successfully resolved complex issues and provided technical guidance via email

• I maintain a professional and empathetic tone in all customer interactions

I am highly skilled in automating infrastructure using scripting and coding.

• Proficient in scripting languages like Python, Bash, and PowerShell

• Experience in using configuration management tools like Ansible and Chef

• Familiarity with cloud platforms like AWS and Azure and their automation tools

• Implemented infrastructure as code using tools like Terraform

• Automated deployment pipelines using tools like Jenkins and GitLab CI/CD

• Examples: Wrote Python scripts to automate AWS EC2 ins...read more

Using Java Stream to find the second highest number, Java 8 changes, HashMap and HashSet internal implementation.

• Use Java Stream to sort the numbers in descending order and skip the first element to get the second highest number.

• Java 8 introduced lambda expressions, functional interfaces, Stream API, default methods in interfaces, and new Date and Time API.

• HashMap uses buckets to store key-value pairs, while HashSet uses HashMap internally to store unique elements.

• HashMap all...read more

Singleton Design Pattern ensures only one instance of a class exists. No, we cannot create a clone of an object from singleton class.

• Singleton pattern restricts the instantiation of a class to one object.

• It is used when only one object is required to coordinate actions across the system.

• The instance is created only when it is requested for the first time.

• The constructor of the singleton class is private.

• Clone method is not supported in singleton pattern.

Yes, I have experience working with semantic tags in HTML.

• Used semantic tags like <header>, <nav>, <main>, <section>, <article>, <aside>, <footer> for better structure and SEO.

• Understand the importance of using semantic tags for accessibility and search engine optimization.

• Semantic tags help in organizing content and making it more readable for developers and browsers.

Various state management techniques in React include Context API, Redux, and local state.

• Context API: React's built-in solution for passing data through the component tree without having to pass props down manually at every level.

• Redux: A popular state management library for React applications, allowing for a centralized store to manage application state.

• Local state: Managing state within individual components using useState hook or this.state in class components.

useMemo is used to memoize a value, while useCallback is used to memoize a function.

• useMemo is used to memoize a value and recompute it only when its dependencies change.

• useCallback is used to memoize a callback function and prevent unnecessary re-renders.

• Example: useMemo can be used to memoize the result of a complex computation, while useCallback can be used to memoize an event handler function.

A system to sell 10 million burgers in 10 minutes

• Implement a high-traffic online ordering platform

• Utilize pre-ordering and queue management systems to handle the rush

• Have a countdown timer for the 10-minute sale period

• Ensure sufficient stock and staff to meet demand

• Offer limited-time promotions to attract customers

JUnit annotations like @Before, @Test, @After are commonly used with Selenium for test automation.

• Annotations like @Before are used to set up preconditions before each test method is executed.

• Annotations like @Test are used to mark a method as a test method.

• Annotations like @After are used to clean up after each test method is executed.

• Annotations like @Ignore are used to skip a test method.

• Annotations like @RunWith are used to specify a custom test runner.

Create a web app to fetch data from an API and implement a search feature for user interaction.

• Use Fetch API to retrieve data from a public API, e.g., JSONPlaceholder.

• Implement a search input box that filters results based on user input.

• Display results in a user-friendly format, such as a list or table.

• Handle loading states and errors gracefully to enhance user experience.

• Consider using a framework like React or Vue.js for better state management.

The thief must maximize stolen money from non-adjacent houses, using dynamic programming for optimal solution.

• Dynamic Programming Approach: Use an array to store the maximum money that can be stolen up to each house.

• Recurrence Relation: For each house, decide to either steal from it (adding its value to the max of two houses before) or skip it.

• Base Cases: If there are no houses, max money is 0; if one house, max money is its value.

• Example: For houses with values [2, 7, 9, 3, ...read more

RESTful services are web services that follow the REST architecture while WebAPI is a framework for building RESTful services.

• RESTful services use HTTP methods like GET, POST, PUT, DELETE to perform CRUD operations on resources

• WebAPI is a framework for building RESTful services using .NET framework

• WebAPI provides features like routing, model binding, content negotiation, etc.

• RESTful services can be consumed by any client that can make HTTP requests

• WebAPI can be used to build ...read more

Junk dimension contains non-additive, unrelated attributes. Degenerate dimension is a dimension key without its own dimension table.

• Junk dimension combines several low-cardinality attributes into a single dimension table.

• Degenerate dimension is a dimension key stored in fact table, not having its own dimension table.

• Example of junk dimension: combining flags like 'is_active', 'is_deleted' into a single table.

• Example of degenerate dimension: order number in a sales fact table.

Using SQL's GROUP BY and aggregate functions to summarize data effectively.

• GROUP BY is used to arrange identical data into groups.

• Aggregate functions like COUNT(), SUM(), AVG(), MAX(), and MIN() summarize data.

• Example: SELECT department, COUNT(*) FROM employees GROUP BY department; returns the number of employees in each department.

• You can combine multiple aggregate functions: SELECT department, AVG(salary), MAX(salary) FROM employees GROUP BY department;

• HAVING clause can fil...read more

Code to find frequency of characters in a given string

• Use a hash table to store character frequencies

• Iterate through the string and update the hash table accordingly

• Print the hash table to display the character frequencies

INNER JOIN returns only the rows that have matching values in both tables, while LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• INNER JOIN is used to retrieve rows from both tables that have matching values based on the specified condition.

• LEFT JOIN is used to retrieve all rows from the left table, along with the matched rows from the right table. If there is no match, NULL values are returned for the right table columns.

• Example: If w...read more

Generator functions and symbols in JavaScript. Implementation of const keyword in ES5.

• Generator functions are functions that can be paused and resumed, allowing for lazy evaluation of data.

• Symbols are a new primitive type in ES6 that can be used as unique identifiers.

• To implement const in ES5, we can use Object.defineProperty to create a read-only property on an object.

One design pattern I know is the Singleton pattern, which ensures a class has only one instance and provides a global point of access to it.

• Singleton pattern can be implemented in scenarios where only one instance of a class is needed, such as a logger class or a configuration class.

• It is commonly used in database connections, thread pools, and caching mechanisms.

• Example: Implementing a Singleton pattern for a database connection class to ensure only one connection is establi...read more

Interfaces define contracts for behavior while abstract classes provide partial implementation.

• Interfaces cannot have implementation while abstract classes can have partial implementation.

• A class can implement multiple interfaces but can inherit from only one abstract class.

• Interfaces are used for loose coupling while abstract classes are used for code reuse.

• Example: An interface 'Drawable' can define a method 'draw' which any class implementing it must define. An abstract cl...read more

The output will depend on the implementation of the method.

• The method may or may not modify the value of the int parameter.

• The method may or may not return a value based on the int parameter.

• Without knowing the implementation of the method, it is impossible to predict the output.

Types of facts in data warehousing include additive, semi-additive, and non-additive facts.

• Additive facts: can be summed up across all dimensions. Example: sales amount.

• Semi-additive facts: can be summed up across some dimensions but not all. Example: inventory levels.

• Non-additive facts: cannot be summed up across any dimension. Example: average temperature.

Selenium supports various navigation commands for interacting with web pages.

• Some navigation commands supported by Selenium include get(), navigate().to(), navigate().back(), navigate().forward(), and navigate().refresh().

• The get() command is used to open a webpage by providing the URL as a parameter.

• The navigate().to() command is used to navigate to a specific URL.

• The navigate().back() command is used to navigate back to the previous page in the browser history.

• The navigate(...read more