Harbinger Systems Interview Questions and Answers

Factory pattern creates objects without exposing the instantiation logic, while Abstract Factory pattern provides an interface for creating families of related objects.

• Factory pattern is a creational design pattern that provides a way to create objects without specifying the exact class of object that will be created.

• Abstract Factory pattern is a creational design pattern that provides an interface for creating familie...read more

Design a scalable system for millions of users

• Use microservices architecture to break down the system into smaller, independent services

• Implement load balancing to distribute traffic evenly across servers

• Utilize caching mechanisms to reduce database load and improve performance

• Use horizontal scaling by adding more servers to handle increased traffic

• Implement monitoring and alerting systems to track system performance a

Kafka implementation in Spring Boot allows for easy integration of Kafka messaging system in Java applications.

• Use Spring Kafka to configure Kafka properties in Spring Boot application

• Create Kafka producer and consumer beans to send and receive messages

• Use @KafkaListener annotation to listen for messages on specific topics

Kafka deletes messages based on retention policies and compaction

• Kafka deletes messages based on retention policies set at topic level

• Messages can also be deleted through log compaction process

• Retention policies can be based on time or size of messages

Kafka configuration involves setting up properties like broker, topic, partitions, replication factor, etc.

• Configure Kafka broker properties in server.properties file

• Create topics using kafka-topics.sh script

• Set up partitions and replication factor for fault tolerance

• Adjust consumer and producer configurations as needed

Structured logs have a predefined format for easy parsing, while unstructured logs do not.

• Structured logs are easier to search, filter, and analyze compared to unstructured logs.

• Unstructured logs can be harder to parse and may require more manual effort to extract useful information.

• Examples of structured logs include JSON or CSV format, while unstructured logs may be plain text or free-form messages.

Microservices communicate through lightweight protocols like HTTP, messaging queues, and RPC.

• Microservices can communicate over HTTP using RESTful APIs.

• Message queues like RabbitMQ or Kafka can be used for asynchronous communication between microservices.

• Remote Procedure Calls (RPC) can be used for synchronous communication between microservices.

• Service discovery mechanisms like Eureka or Consul help microservices loca...read more

I chose this company because of its innovative projects, strong team culture, and opportunities for growth.

• Innovative projects that challenge me to learn and grow

• Strong team culture that fosters collaboration and support

• Opportunities for career growth and advancement

Seeking new challenges and growth opportunities in a dynamic environment.

• Looking to expand skill set and knowledge in Java development

• Interested in working on innovative projects and technologies

• Seeking a more collaborative and supportive work culture