Apisero Senior Software Engineer Interview Questions and Answers

API stands for Application Programming Interface. REST and SOAP are two types of APIs.

• REST is an architectural style that uses HTTP protocol for communication and supports multiple data formats like JSON, XML, etc.

• SOAP is a protocol that uses XML for communication and supports only XML data format.

• REST is lightweight and easy to use, while SOAP is more complex and requires more bandwidth.

• REST is stateless, while SOAP m...read more

oAuth tokens are used for authentication and authorization purposes in web applications.

• oAuth tokens are used to grant access to resources without sharing the user's credentials.

• There are three types of oAuth tokens: access tokens, refresh tokens, and authorization codes.

• Access tokens are short-lived tokens that are used to access protected resources.

• Refresh tokens are long-lived tokens that are used to obtain new acce...read more

Stored Procedures are pre-compiled SQL statements stored in the database and executed on demand.

• Stored Procedures are used to improve performance by reducing network traffic and improving security.

• They can be used to encapsulate business logic and provide a consistent interface to the database.

• They can be called from other PL/SQL code or from external applications.

• Examples include procedures for inserting, updating, an...read more

Drop command removes a table from the database, truncate command removes all rows from a table, and delete command removes specific rows from a table.

• Drop command removes the table structure and all associated data

• Truncate command removes all rows from a table but keeps the table structure

• Delete command removes specific rows from a table based on a condition

• Drop and truncate are faster than delete as they do not genera...read more

Merge Sort and Quick Sort are sorting algorithms. Merge Sort is stable but slower. Quick Sort is faster but unstable.

• Merge Sort divides the array into two halves, sorts them recursively, and then merges them.

• Quick Sort selects a pivot element, partitions the array around the pivot, and then recursively sorts the subarrays.

• Merge Sort has a time complexity of O(nlogn) and space complexity of O(n).

• Quick Sort has a time co...read more

Object Oriented Programming is a programming paradigm that focuses on objects and their interactions.

• OOP is based on the concepts of encapsulation, inheritance, and polymorphism.

• It allows for modular and reusable code.

• Objects have attributes (data) and methods (functions) that operate on that data.

• Examples of OOP languages include Java, Python, and C++.

Armstrong number problem solved using double pointers.

• Use double pointers to access each digit of the number.

• Calculate the sum of each digit raised to the power of the number of digits.

• Compare the sum with the original number to check if it is an Armstrong number.

VPC stands for Virtual Private Cloud, which is a virtual network in the cloud.

• VPC allows users to create their own isolated network within the cloud

• It provides control over network topology, IP address range, and subnets

• VPC can be used to securely connect resources in the cloud and on-premises

• Examples of cloud providers that offer VPC are Amazon Web Services and Google Cloud Platform

On-premises servers can be connected to the Cloud using VPN or Direct Connect.

• Use a VPN to establish a secure connection between on-premises servers and the Cloud.

• Direct Connect can be used for a dedicated, private connection between on-premises servers and the Cloud.

• Ensure proper network configuration and security measures are in place.

• Examples of VPN solutions include OpenVPN, Cisco AnyConnect, and AWS VPN.

• Examples o...read more

Multithreading is the execution of multiple threads of a single process, while multiprocessing is the execution of multiple processes.

• Multithreading involves multiple threads within a single process, while multiprocessing involves multiple processes.

• Multithreading shares the same memory space, while multiprocessing has separate memory spaces.

• Multithreading is suitable for I/O-bound tasks, while multiprocessing is suita...read more

I handle exceptions by catching them and handling them appropriately.

• I use try-catch blocks to catch exceptions.

• I log the exception details for debugging purposes.

• I handle the exception based on the type and severity.

• I throw custom exceptions when necessary.

• I ensure that the application remains stable and doesn't crash due to exceptions.

Generators and decorators are two important features in Python that help in simplifying code and improving performance.

• Generators are functions that can be paused and resumed, allowing for efficient memory usage and lazy evaluation.

• Decorators are functions that modify the behavior of other functions, adding functionality without changing the original code.

• Generators are created using the 'yield' keyword, while decorato...read more

A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.

• A prime number has exactly two distinct positive divisors: 1 and itself.

• Examples of prime numbers include 2, 3, 5, 7, 11, and 13.

• The number 1 is not prime, and 2 is the only even prime number.

• To check if a number n is prime, test divisibility from 2 to sqrt(n).

• For example, to check if 29 is prime, test div...read more

Find the two maximum numbers in an array of strings.

• Convert the array of strings to an array of integers.

• Sort the array in descending order.

• Return the first two elements of the sorted array.

Java is platform independent due to its bytecode and the Java Virtual Machine (JVM) that allows execution on any OS.

• Java code is compiled into bytecode, which is platform-independent.

• The Java Virtual Machine (JVM) interprets bytecode on any operating system.

• This allows Java applications to run on Windows, macOS, Linux, etc., without modification.

• Example: A Java program compiled on Windows can run on Linux without recom...read more

Primary key uniquely identifies a record in a table, while foreign key establishes a link between two tables.

• Primary key is used to enforce data integrity and ensure uniqueness of records.

• Foreign key is used to establish relationships between tables and enforce referential integrity.

• A table can have only one primary key, while it can have multiple foreign keys.

• Primary key can be used as a foreign key in another table.

• E...read more

REST API is lightweight and flexible, while SOAP is more structured and secure.

• REST uses HTTP protocol and supports multiple data formats like JSON, XML, etc.

• SOAP uses XML protocol and supports only XML data format.

• REST is faster and consumes less bandwidth than SOAP.

• SOAP has built-in security features like WS-Security and WS-Trust.

• REST is easier to implement and maintain than SOAP.

• SOAP is better suited for enterprise-...read more

List is mutable and ordered while Tuple is immutable and ordered.

• List can be modified while Tuple cannot be modified.

• List is represented by square brackets [] while Tuple is represented by parentheses ().

• List is used for homogeneous data while Tuple is used for heterogeneous data.

Annotations in Spring Boot and their meanings

• 1. @SpringBootApplication - used to mark the main class of a Spring Boot application

• 2. @RestController - used to mark a class as a RESTful controller

• 3. @Autowired - used to inject dependencies into a class

• 4. @RequestMapping - used to map HTTP requests to methods in a controller

• 5. @PathVariable - used to extract values from the URI in a request mapping

• 6. @RequestBody - used t...read more