1st Round (DSA + Technical): 1.5 hours

**Theory: **

• Java 11 new features , Java 8 new features
• Functional interfaces - ones introduced in Java 8
• Lambda functions : uses, examples
• How generics work under the hood
• Exception hierarchy in java
• Hashmap internal working
• HashSet vs HashMap
• Polymorphism in java : types and how they work
• Streams - uses
• Method overloading vs overriding
• Transaction management in Spring/Hibernate
• REST api - good practices

Coding:

• Given an array of strings, group the anagrams together Input: strs = ["eat","tea","tan","ate","nat","bat"] Output: [["bat"],["nat","tan"],["ate","eat","tea"]]
• Given a string array of sentences use stream api to return distinct list of words that start with #
  • String[] sentences = {
    "Here is a #sample sentence.",
    "This is another #example of a sentence.",
    "#Java streams are powerful.",
    "Find words that start with #."
    };

Note: Coding has to be done in an online editor provided by interviewer. Do-not expect auto-indentation or syntax-suggestions. Even run/execute button is disabled (Only interviewer can execute)

2nd Round (DSA + Technical) : 1.5 hours

• Introduce yourself : skills, tech-stack, projects
• Features introduced in Java 8 , Use of Streams, functional interfaces
  • Stream related basic Java program
• CAP theorem
• SAGA pattern
• Spring boot annotations : @Qualifier , @Primary
• Normalization in DB: why to normalize, types of normalization
• Design a Popularity counter class with methods,
  • incCounter(String uid);
  • decCounter(String uid);
  • getMostPopularContent();
• https://leetcode.com/problems/task-scheduler/description/

3rd round (Techno-managerial) : 1 hr

• Introduce yourself : skills, tech-stack, projects
• Explain architecture in detail of current project that you’re working on. Draw using draw.io
• Explain each component of the micro-services architecture:
  • Service registry -how it works, what is heartbeat message ? where is it configured and what parameters.
  • API gateway : Deep dive into internal working and configuration, how it routes request to an instance of a service
  • Config server : what configurations are stored and how it is fetched by services
  • Explain the steps/configuration changes needed if you have to introduce a new micro-service to the current application — (IN DEPTH)
  • How microservice communication is handled - synchronous vs asynchronous (RESTTemplate , FeignClient)
  • Microservice patterns : 2PC, Saga, CQRS (Questions related to practical implementation) ,drawbacks of Saga
  • How monitoring is done in current project
  • How logging is implemented : In depth steps/algo how log aggregation (like ELK ) works internally
  • CI/CD used in current project (Jenkins) : How CI/CD pipeline works for a Java application via Jenkins (In depth)
• Mention 2 challenging/critical features you have implemented or fixed