PayU Payments Interview Questions, Process, and Tips

Joins in SQL are used to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column.

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RI...read more

The maximum salary in the employee table can be found by querying the database for the highest salary value.

• Query the employee table for the maximum salary using SQL: SELECT MAX(salary) FROM employee;

• Check for any outliers or errors in the salary data before determining the maximum value.

• Consider any potential bonuses or additional compensation that may affect the salary values.

Common types of microservices include API gateways, service discovery, and event-driven architecture.

• API gateways: Acts as a single entry point for multiple microservices, handling authentication, routing, and load balancing.

• Service discovery: Allows microservices to find and communicate with each other dynamically, without hardcoding IP addresses.

• Event-driven architecture: Microservices communicate through events, ena...read more

I have used RESTful APIs, SOAP APIs, and GraphQL APIs in my previous projects.

• RESTful APIs: Used for creating, updating, reading, and deleting resources over HTTP.

• SOAP APIs: Used for exchanging structured information in the implementation of web services.

• GraphQL APIs: Used for querying specific data requirements and receiving a predictable response.

ITSM tools are software solutions that help organizations manage and optimize their IT services.

• Incident management tools

• Change management tools

• Problem management tools

• Asset management tools

• Service catalog tools

• Service desk tools

The type of database used is a relational database management system (RDBMS).

• Uses tables to store data

• Supports SQL for querying and managing data

• Examples include MySQL, PostgreSQL, Oracle

VLOOKUP formulas are used in Excel to search for a value in a table and return a corresponding value from another column.

• VLOOKUP with exact match: =VLOOKUP(lookup_value, table_array, col_index_num, FALSE)

• VLOOKUP with approximate match: =VLOOKUP(lookup_value, table_array, col_index_num, TRUE)

• VLOOKUP with wildcard characters: =VLOOKUP(CONCATENATE('*', lookup_value, '*'), table_array, col_index_num, FALSE)

I use Grafana and Kibana dashboards for monitoring purposes.

• Grafana is used for visualizing time series data and monitoring metrics.

• Kibana is used for analyzing and visualizing logs and other time-series data.

Max diameter of a tree in Java is the longest path between any two nodes in a tree.

• The diameter of a tree can be calculated by finding the longest path between any two nodes in the tree.

• This can be done by finding the longest path from the root to a leaf node, and then finding the longest path from another leaf node to the root.

• The sum of these two paths gives the diameter of the tree.

Merge two sorted linked lists into a single sorted linked list

• Create a new linked list to store the merged result

• Iterate through both input linked lists and compare nodes to determine the order in which they should be added to the result list

• Handle cases where one list is longer than the other

To check if parentheses are balanced, use a stack data structure to keep track of opening and closing parentheses.

• Use a stack to push opening parentheses and pop when encountering a closing parenthesis

• If stack is empty when encountering a closing parenthesis, return false

• After iterating through all parentheses, if stack is empty, return true

The right view of a Binary Search Tree shows the nodes that are visible when viewing the tree from the right side.

• The right view of a Binary Search Tree includes the rightmost node at each level.

• Nodes at each level that are not visible from the right side are not included in the right view.

• Example: For the Binary Search Tree with values 1, 2, 3, 4, 5, the right view would be 1, 3, 5.

OOPS is Object-Oriented Programming, Inheritance is the ability of a class to inherit properties and behavior from another class, Static Binding is resolved at compile time, Dynamic Binding is resolved at runtime.

• OOPS stands for Object-Oriented Programming, which is a programming paradigm based on the concept of objects.

• Inheritance is a feature in OOP that allows a class to inherit properties and behavior from another ...read more