ZapCom Group Interview Questions and Answers

Find index of second smallest and second largest element in an array of strings

• Convert the array of strings to an array of integers for comparison

• Sort the array to easily find the second smallest and second largest elements

• Track the indices of the elements as you iterate through the sorted array

Convert a number into words

• Create an array of strings to represent numbers from 0 to 19

• Use conditional statements to handle numbers from 20 to 99

• Consider special cases like multiples of 10 and teens

Join is used to combine rows from two or more tables based on a related column, while subquery is a query nested within another query.

• Join is used to retrieve data from multiple tables based on a related column

• Subquery is a query nested within another query

• Join is typically more efficient than subqueries for large datasets

• Example: SELECT * FROM table1 JOIN table2 ON table1.id = table2.id

• Example: SELECT * FROM table WHERE id IN (SELECT id FROM another_table)

Load balancer design involves distributing incoming network traffic across multiple servers to ensure optimal resource utilization and prevent overload.

• Consider the type of traffic being balanced (HTTP, TCP, UDP)

• Choose between hardware or software load balancers based on requirements

• Implement algorithms like round-robin, least connections, or IP hash for load distribution

• Ensure high availability by setting up redundant load balancers

• Monitor and adjust load balancer settings t...read more

Kafka is a distributed streaming platform while Zookeeper is a centralized service for maintaining configuration information.

• Kafka is used for building real-time data pipelines and streaming apps

• Zookeeper is responsible for managing and coordinating Kafka brokers

• Zookeeper stores metadata about Kafka cluster and helps in leader election

• Kafka brokers use Zookeeper to discover other brokers and to maintain topic partition information