DEV Community: Poojitha

Agile and Scrum Methodology Interview Questions

Poojitha — Sun, 07 Jun 2026 08:27:30 +0000

What is Waterfall model?
What is Agile Model?
What is scrum framework?
What is product backlog?
What is sprint backlog?
What is sprint review?
What is user Stories?
What is story points?
What is sprint retrospective meeting?

Java Interview Questions

Poojitha — Fri, 05 Jun 2026 04:18:18 +0000

1.Who is the founder of Java?
Ans.James Gosling and team who works at SunMicrosystem.
2.What are the features of Java?
Ans.

High Level Language
Platform Independent: write once run anywhere (WORA).
Object Oriented Programming Language.
Strictly Typed Language
Robust and secure
Automatic Garbage Collection
Multi Threading
Backward Compatibility

3.what is the Latest version of Java?
Ans. java 26
4.Can we compile a Java code without a main method?
Ans.Yes
Explanation:As we know compiler checks for syntax.
5.Can we run the a Java code without a main method?
Ans.No
6.Is Java compiled or Interpreted?
Ans. java is a hybrid language.
7.what is the difference between JDK, JRE and JVM?
8.Explain Jvm architecture?
Class Loader sub system:
Load .class files to jvm
And verifies.class files and it finds vulnerabilities if it is there
Memory management:
Method area-
Static variables will be stored area
Heap area-
Instance variables
Objects will be stored inside heap area.
Stack area-
Local variables
Threads
Program counters -
Holds the current and next instructions
Native method area-
Java-> python, c
Execution Engine:
=>Interprator
=>JIT Compiler
=>Garbage Collector

Spring boot Interview Questions

Poojitha — Fri, 22 May 2026 18:18:21 +0000

1. What is CORS and why is it required?
CORS (Cross-Origin Resource Sharing) is a browser security mechanism that allows/restricts APIs from being accessed by another domain.
Example:
Frontend: http://localhost:3000
Backend API: http://localhost:8080
These are different origins because ports are different.
Without CORS configuration, browser blocks the request.
Why required?
To securely allow frontend applications to call backend APIs hosted on different domains/ports.
Interview Answer:
CORS is a browser security feature that controls cross-origin HTTP requests. It is required when frontend and backend run on different domains, ports, or protocols. In Spring Boot, we configure CORS to allow trusted origins to access APIs securely.
2. How do you configure CORS in Spring Boot?
Using @CrossOrigin
Java
@RestController
@CrossOrigin(origins = "http://localhost:3000")
public class UserController {
}
Global Configuration
Java
@Configuration
public class CorsConfig {

@Bean
public WebMvcConfigurer corsConfigurer() {
    return new WebMvcConfigurer() {
        @Override
        public void addCorsMappings(CorsRegistry registry) {
            registry.addMapping("/**")
                    .allowedOrigins("http://localhost:3000")           .allowedMethods("GET", "POST", "PUT", "DELETE");
        }
    };
}

}
Real-time usage:
In production, React/Angular frontend calls Spring Boot APIs from another domain.

3. What is CSRF attack?
CSRF = Cross Site Request Forgery
It tricks a logged-in user into performing unwanted actions.
Example:
User logged into banking site
Malicious website sends transfer request automatically
Browser sends session cookie
Server thinks request is genuine
Interview Answer:
CSRF attack occurs when a malicious site tricks an authenticated user into sending unauthorized requests to another application where the user is already logged in.

application.properties

Poojitha — Fri, 22 May 2026 11:11:17 +0000

1.spring.datasource.hikari.connectionTimeout
Meaning:
How long an application waits to get a DB connection from the pool before throwing an exception.
Ex:
spring.datasource.hikari.connectionTimeout=30000
= Wait for 30 seconds
Real-time Scenario
Suppose:
All DB connections are busy
New request comes
Application asks pool for connection
If no connection becomes available within 30 seconds:
Plain text
SQLTransientConnectionException:
Connection is not available, request timed out

2.spring.datasource.hikari.idleTimeout
Meaning:
How long an unused/idle connection stays in pool before being removed.
Unit
Milliseconds
Example
Properties
spring.datasource.hikari.idleTimeout=600000
= 10 minutes
Real-time Understanding
Suppose:
Your app created 20 DB connections
Only 5 are being used
Remaining 15 are idle
After idleTimeout duration:
Extra unused connections may be closed
Helps save DB resources
Important Point
This works mainly when:
Plain text
minimumIdle < maximumPoolSize
Otherwise pool keeps all connections alive.

3.spring.datasource.hikari.maximumPoolSize
Meaning
Maximum number of DB connections allowed in pool.
Example
Properties
spring.datasource.hikari.maximumPoolSize=20
Maximum 20 DB connections can exist.
Real-time Scenario
Suppose:
20 requests are using DB connections
21st request comes
Then:
It waits for available connection
Until connectionTimeout occurs

4.spring.datasource.hikari.minimumIdle
Meaning
Minimum number of idle connections always maintained in pool.
Example
Properties
spring.datasource.hikari.minimumIdle=5
Even if connections are unused:
Hikari keeps at least 5 ready connections
Real-time Benefit
When traffic suddenly increases:
App gets DB connections immediately
No delay creating new connection