HPI Limited Technical Support Engineer Interview Questions and Answers

Connecting to a database has multiple options depending on the type of database and programming language used.

• For SQL databases, options include using JDBC for Java, ODBC for C++, and ADO.NET for C#.

• For NoSQL databases, options include using MongoDB's driver for Python or Node.js.

• ORMs like Hibernate and Entity Framework can also be used to abstract away the database connection details.

• Connection strings are used to spe...read more

Implement stack data structure

• Use an array or linked list to store elements

• Push operation adds element to top of stack

• Pop operation removes element from top of stack

• Peek operation returns top element without removing it

Global variables are accessible from any part of the program and can be modified by any function.

• Global variables are declared outside of any function.

• They can be accessed and modified by any function in the program.

• If a function modifies the value of a global variable, the new value is visible to all other functions.

• Global variables can be useful for sharing data between functions.

• However, overuse of global variables

Program to transpose a matrix

• Iterate through rows and columns of the matrix

• Swap the elements at (i,j) and (j,i) positions

• Return the transposed matrix

Pre and post fix operators are used to increment or decrement a value before or after it is used in an expression.

• Pre-fix operator (++x) increments the value of x and returns the new value.

• Post-fix operator (x++) returns the value of x and then increments it.

• Both operators can be used with variables of numeric data types.

• They can also be used with pointers to increment or decrement the memory address they point to.

Microservices offer benefits such as scalability, flexibility, and easier maintenance.

• Scalability: Microservices can be scaled independently, allowing for better resource utilization.

• Flexibility: Microservices can be developed and deployed independently, allowing for faster iteration and innovation.

• Easier maintenance: Microservices are smaller and more focused, making it easier to identify and fix issues.

• Improved fault...read more

Spring is a framework while Spring Boot is an extension of Spring.

• Spring Boot provides auto-configuration and embedded servers.

• Spring Boot reduces boilerplate code and simplifies application setup.

• Spring Boot is opinionated and provides defaults for configuration.

• Spring Boot is ideal for microservices and standalone applications.

• Spring is more flexible and customizable than Spring Boot.

Yes, I have configured service registry.

• I have experience with service registry tools like Consul and Eureka.

• I have configured service registry for microservices architecture.

• I have implemented service discovery and load balancing using service registry.

• I have used service registry to manage service endpoints and metadata.

Profile registry is used to store user profiles and their preferences in a centralized location.

• Profile registry is used to manage user profiles and preferences in a centralized location

• It can be configured in a project by defining the schema for user profiles and preferences

• Profile registry can be accessed through APIs or SDKs

• It can be used to personalize user experience and provide targeted content

• Examples of profile...read more

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

• Spring Boot uses an embedded server to run applications.

• It provides auto-configuration for commonly used libraries and frameworks.

• Spring Boot uses Spring Framework's core features like Inversion of Control (IoC) and Aspect Oriented Programming (AOP).

• It uses annotations to configure and c...read more

We can handle the situation by implementing fault tolerance mechanisms.

• Implementing circuit breakers to prevent cascading failures

• Using load balancers to redirect traffic to healthy instances

• Implementing retry mechanisms to handle temporary failures

• Using monitoring tools to detect and alert on failures

• Implementing graceful degradation to provide partial functionality

• Using backups or replicas to ensure high availability

We use @RestController, @RequestMapping, @Autowired, @Service, @Repository, @Transactional, @GetMapping, @PostMapping, @PutMapping, @DeleteMapping annotations in our Spring Boot project.

• @RestController - used to define RESTful web services

• @RequestMapping - used to map HTTP requests to handler methods

• @Autowired - used for automatic dependency injection

• @Service - used to define a service layer component

• @Repository - used...read more

Spring Data JPA simplifies the implementation of data access layer in Spring applications.

• Provides a framework for easily creating repositories and queries

• Reduces boilerplate code for data access layer

• Supports pagination and sorting of data

• Integrates with Spring's transaction management

• Example: @Repository interface UserRepository extends JpaRepository {}

A hash map is a data structure that uses a hash function to map keys to values in constant time.

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

• The hash function is used to convert the key into an index of the array

• Collisions occur when two keys map to the same index, which is resolved using chaining or open addressing

• Retrieving a value from a hash map involves computing the hash of the key and then looking up the corre...read more

Comparable is an interface used for natural ordering while Comparator is an interface used for custom ordering.

• Comparable is implemented by the class itself while Comparator is implemented by a separate class.

• Comparable provides a single method compareTo() while Comparator provides a single method compare().

• Comparable is used for sorting elements in a collection while Comparator is used for custom sorting.

• Example: Stri...read more

Concurrent Hash Map is a thread-safe implementation of a hash map.

• It allows multiple threads to access and modify the map concurrently.

• It uses a technique called lock striping to achieve high concurrency.

• It is part of the java.util.concurrent package in Java.

• Example: ConcurrentHashMap in Java.