10+ Hyoseong Electric Interview Questions and Answers

Explaining Spring concepts: Qualifier, Autowired, Bean scope, and Dependency management

• Qualifier is used to specify which bean to inject when multiple beans of the same type are present

• Autowired automatically injects a bean by type, but can also use Qualifier to specify which bean to inject

• Bean scope determines the lifecycle of a bean, such as singleton or prototype

• Dependency management ensures that all required dependencies are available before a bean is created

Microservices are a way to design software applications as a collection of small, independent services that communicate with each other via APIs.

• Microservices are a software architectural style where applications are composed of small, independent services that communicate over well-defined APIs.

• APIs (Application Programming Interfaces) are a set of rules and protocols that allow different software applications to communicate with each other.

• Microservices use APIs to interact...read more

Query to select IDs from table one not present in table two

• Use a LEFT JOIN to combine the two tables

• Filter the results where the ID from table one is NULL in table two

Select student list for 3rd most highest mark from the student table.

• Order the student table by marks in descending order

• Skip the first two highest marks

• Select the student list for the 3rd highest mark

Class loader is a part of Java Runtime Environment (JRE) that loads classes and interfaces at runtime.

• Class loader is responsible for locating and loading the necessary class files into memory.

• It follows a hierarchical structure and delegates the class loading to parent class loaders.

• Class loaders can be customized to load classes from different sources like file system, network, or database.

• They provide a level of security by separating different class namespaces.

• Examples of...read more

Developing software services involves designing, implementing, testing, and deploying services that meet user requirements.

• Identify user requirements and design the service architecture accordingly

• Implement the service using appropriate programming languages and frameworks

• Test the service thoroughly to ensure it meets user requirements and is reliable

• Deploy the service to a production environment and monitor its performance

• Continuously improve the service based on user feedba...read more

Sample Interface with Implementation for a Senior Software Developer interview

• Create an interface with method signatures

• Implement the interface in a class

• Use the interface to define behavior in other classes

Java 8 introduced Streams API for processing collections of data in a functional style.

• Streams provide a way to work with sequences of elements in a declarative manner.

• Features include map, filter, reduce, and collect operations.

• Streams can be parallelized to improve performance.

• Example: List<String> names = Arrays.asList("Alice", "Bob", "Charlie"); Stream<String> stream = names.stream();

• Example: int sum = numbers.stream().filter(n -> n % 2 == 0).mapToInt(n -> n * 2).sum();

final is a keyword in Java used to declare a constant value. finally is a block used in exception handling to ensure a piece of code is always executed.

• final is used to declare a variable whose value cannot be changed

• finally is used in a try-catch block to specify a block of code that will always be executed, regardless of whether an exception is thrown or not

Microservices are a software development technique where applications are broken down into smaller, independent services that communicate with each other.

• Microservices are designed to be small, focused, and independently deployable services.

• Each microservice typically performs a single function or task.

• Microservices communicate with each other through APIs.

• They can be developed, deployed, and scaled independently.

• Examples of companies using microservices include Netflix, Amaz...read more

Structural directives in Angular are used to modify the DOM layout by adding, removing, or manipulating elements based on conditions.

• Structural directives are preceded by an asterisk (*) in Angular templates.

• Common structural directives include *ngIf, *ngFor, and *ngSwitch.

• They allow developers to conditionally render or remove elements from the DOM.

• Example:

  Content

Spring Actuator is a feature in Spring Boot that provides endpoints to monitor and interact with the application.

• Provides insight into application's health, metrics, and other information

• Includes endpoints like /health, /info, /metrics, etc.

• Can be customized and extended to add custom endpoints

ArrayList is a resizable array implementation in Java.

• ArrayList is a class in Java's Collection framework.

• It provides dynamic resizing, unlike regular arrays.

• It can store objects of any type, including strings.

• ArrayLists can grow or shrink dynamically as elements are added or removed.

• Example: ArrayList names = new ArrayList();

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• HashMap is part of the Java Collections Framework.

• It allows null values and null keys.

• Keys must be unique, but values can be duplicated.

• Basic operations include put(key, value), get(key), remove(key), and containsKey(key).

• Example: HashMap map = new HashMap<>();

Middleware is software that acts as a bridge between different applications or components, allowing them to communicate and share data.

• Middleware facilitates communication between different software applications or components

• It can handle tasks such as data transformation, security, and routing

• Examples of middleware include message brokers like RabbitMQ, web servers like Apache Tomcat, and API gateways like Kong