20+ Technology Consultant Interview Questions and Answers for Freshers

IPv6 is needed due to the exhaustion of IPv4 addresses and the need for more secure and efficient communication.

• IPv4 has a limited number of addresses, which are almost exhausted

• IPv6 provides a much larger address space, allowing for more devices to connect to the internet

• IPv6 also offers improved security features and more efficient routing

• Many new devices and networks are already using IPv6

• IPv6 is essential for the future growth and development of the internet

Find the smallest subarray in an array with exactly K distinct elements.

• Use a sliding window approach to keep track of the subarray with K distinct elements.

• Use a hashmap to store the frequency of each element in the window.

• Update the window by expanding or shrinking based on the number of distinct elements.

• Return the smallest subarray with K distinct elements and the smallest leftmost index.

Single variant parameters have one value while multivariant parameters have multiple values.

• Single variant parameters have only one value that can be changed.

• Multivariant parameters have multiple values that can be changed.

• Examples of single variant parameters include age, weight, and height.

• Examples of multivariant parameters include hair color, eye color, and skin tone.

Code to check if a given string is a palindrome or not.

• Remove all non-alphanumeric characters from the string

• Convert the string to lowercase

• Reverse the string and compare with the original string

• If they are equal, then the string is a palindrome

ArrayList is non-synchronized and Vector is synchronized in Java.

• ArrayList is not synchronized, while Vector is synchronized.

• ArrayList is faster than Vector.

• Vector is thread-safe, while ArrayList is not.

• Example: ArrayList<String> list = new ArrayList<>(); Vector<String> vector = new Vector<>();

The @RestController annotation in Spring Boot is used to define a class as a RESTful controller.

• Used to create RESTful web services in Spring Boot

• Combines @Controller and @ResponseBody annotations

• Eliminates the need for @ResponseBody annotation on each method

• Returns data directly in the response body as JSON or XML

HashSet is a collection of unique elements, while HashMap is a key-value pair mapping.

• HashSet does not allow duplicate elements, HashMap allows duplicate keys but not values.

• HashSet uses a hash table to store elements, HashMap uses key-value pairs.

• Example: HashSet<String> set = new HashSet<>(); HashMap<String, Integer> map = new HashMap<>();

Java Strings are immutable to ensure thread safety, security, and optimization.

• Immutable strings prevent accidental changes, ensuring data integrity.

• String pooling allows for memory optimization by reusing common strings.

• Thread safety is guaranteed as strings cannot be modified concurrently.

• Security is enhanced as sensitive information cannot be altered once set.

Java 8 program to iterate through a Stream using forEach method

• Create a Stream of elements using Stream.of() or any other method

• Use the forEach() method to iterate through the Stream and perform an action on each element

• Example: Stream.of(1, 2, 3, 4, 5).forEach(System.out::println);

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

• Virtualisation allows multiple operating systems to run on a single physical machine.

• Paging is a memory management scheme that allows the operating system to move pages of memory between main memory and secondary storage.

• Thrashing occurs when a computer's operating system spends a lot of time swapping data between RAM and virtual memory, slow...read more

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured setups.

• Auto-configuration: Spring Boot automatically configures the application based on dependencies added to the project.

• Embedded server: Spring Boot comes with an embedded Tomcat, Jetty, or Undertow server for easy deployment.

• Actuator: Provides production-ready features like monitoring, metrics, and health checks for the application.

JIT compiler stands for Just-In-Time compiler, which compiles code during runtime for improved performance.

• JIT compiler translates bytecode into machine code at runtime

• It helps in optimizing performance by compiling frequently executed code

• Examples include Java HotSpot JIT compiler and .NET JIT compiler

MVC in Spring is a design pattern that separates an application into three main components: Model, View, and Controller.

• Model represents the data and business logic of the application.

• View is responsible for rendering the user interface based on the data from the Model.

• Controller acts as an intermediary between Model and View, handling user input and updating the Model accordingly.

• Spring MVC provides annotations like @Controller, @RequestMapping, and @ModelAttribute to implem...read more

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot eliminates the need for manual configuration by providing defaults for most settings.

• It includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to run applications as standalone JAR files.

• Spring Boot also offers production-ready features like metrics, health checks, and externalized configuration.

• It allows developers to q...read more

Java 8 streams are a sequence of elements that support functional-style operations.

• Streams allow for processing sequences of elements in a functional way.

• They can be created from various data sources like collections, arrays, or I/O channels.

• Operations like filter, map, reduce, and collect can be performed on streams.

• Streams are lazy, meaning intermediate operations are only executed when a terminal operation is called.

• Example: List<String> names = Arrays.asList("Alice", "Bob...read more

Dependency injection is a design pattern in which components are given their dependencies rather than creating them internally.

• Dependency injection helps in achieving loose coupling between classes.

• It allows for easier testing by providing mock dependencies.

• There are three types of dependency injection: constructor injection, setter injection, and interface injection.

Use SQL query to find top 3 salaries from each department in employee table.

• Use window functions like ROW_NUMBER() to rank salaries within each department

• Partition the data by department and order by salary in descending order

• Filter the results to only include rows where the row number is less than or equal to 3

Best practices for technology consultants

• Stay updated on latest technologies and trends

• Communicate effectively with clients and team members

• Document all processes and decisions for future reference

• Provide regular updates and progress reports to stakeholders

• Continuously improve skills through training and certifications

PwC is known for providing professional services in the areas of audit, tax, and consulting.

• Global network of firms offering assurance, tax, and consulting services

• Known for their expertise in various industries such as technology, healthcare, and financial services

• Provides services to help clients solve complex business problems and achieve their goals

JWT syntax for signing and verification

• JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties.

• To sign a JWT, you need to create a header, payload, and a secret key. Then use a signing algorithm like HMAC SHA256 to create the signature.

• To verify a JWT, you need to decode the JWT and verify the signature using the same secret key and algorithm used for signing.

Complex queries can be handled by breaking them down into smaller parts, using indexes, optimizing the query, and utilizing advanced query techniques.

• Break down the query into smaller parts to make it more manageable

• Use indexes on the columns involved in the query to improve performance

• Optimize the query by analyzing execution plans and making necessary adjustments

• Utilize advanced query techniques such as subqueries, joins, and window functions

Implementing security measures to protect data and systems from unauthorized access.

• Implement strong password policies

• Use encryption for sensitive data

• Regularly update software and systems to patch vulnerabilities

• Implement multi-factor authentication

• Conduct regular security audits and penetration testing

My favourite subject is computer science because I enjoy problem-solving and creating innovative solutions.

• I love learning about algorithms and data structures

• I enjoy programming and coding in languages like Java and Python

• I find networking and cybersecurity fascinating