API Backend Developer Interview Questions
API is an abbreviation for Application Programming Interface which is a collection of communication protocols and subroutines used by various programs to communicate between them. A programmer can make use of various API tools to make their program easier and simpler.
79. What is REST?
Representational State Transfer (REST) is an architectural style that defines a set of constraints to be used for creating web services. REST API is a way of accessing web services in a simple and flexible way without having any processing. REST technology is generally preferred to the more robust Simple Object Access Protocol (SOAP) technology.
80. What is a URI?
URI stands for Uniform Resource Identifier. It is a technical term that used for the names of all resources Connected to the World Wide Web. URIs established the protocols over the internet to conduct the connection between among resources.
81. What is RESTful?
RESTful web services are generally highly scalable, light, and maintainable and are used to create APIs for web-based applications. It exposes API from an application in a secure and stateless manner to the client. The protocol for REST is HTTP.
REST is a software architectural style that defines the set of rules to be used for creating web services. Web services which follow the REST architectural style are known as RESTful web services. There are six architectural constraints which makes any web service are listed below:
- Uniform Interface
- Stateless
- Cacheable
- Client-Server
- Layered System
- Code on Demand
HTTP PUT Request
HTTP PUT is a request method supported by HTTP used by the World Wide Web. The PUT method requests that the enclosed entity be stored under the supplied URI.
import requests
# Making a PUT request
r = requests.put('https://httpbin.org/put', data={'key':'value'})
#check status code for response received
# success code - 200
print(r)
# print content of request
print(r.content)
HTTP POST Request
HTTP POST is a request method supported by HTTP used by the World Wide Web. By design, the POST request method requests that a web server accepts the data enclosed in the body of the request message, most likely for storing it.
import requests
# Making a POST request
r = requests.post('https://httpbin.org/post', data={'key':'value'})
#check status code for response received
# success code - 200
print(r)
# print content of request
print(r.json())
HTTP status codes are a set of standardized three-digit numbers used by web servers to communicate the outcome of an HTTP request made by a client. They provide information about whether the request was successful, encountered an error, or requires further action by the client.
- 1xx – Informational: Request received, continuing process.
- 2xx – Success: The action was successfully received, understood, and accepted.
- 3xx – Redirection: Further action needs to be taken in order to complete the request.
- 4xx – Client Error: The request contains bad syntax or cannot be fulfilled.
- 5xx – Server Error: The server failed to fulfill an apparently valid request.
Each status code has a specific meaning, allowing both clients and servers to understand the outcome of a request and take appropriate action. For example, status code 200 indicates a successful request, while status code 404 indicates that the requested resource was not found on the server.
There are three types of security mechanism for an API –
- HTTP Basic Authentication: In this mechanism HTTP User Agent provides a Username and Password. Since this method depends only on HTTP Header and entire authentication data is transmitted on insecure lines
- API Keys: API Keys came into picture due to slow speed and highly vulnerable nature of HTTP Basic Authentication.
- OAuth: OAuth is not only a method of Authentication or Authorization, but it’s also a mixture of both the methods. Whenever an API is called using OAuth credential, user logs into the system, generating a token.
The Cache-Control header is a general header, that specifies the caching policies of server responses as well as client requests. Basically, it gives information about the manner in which a particular resource is cached, location of the cached resource, and its maximum age attained before getting expired i.e. time to live.
Syntax:
Cache-Control: <directive> [, <directive>]*
The process of connecting two or more software applications or processes using APIs is referred to as API integration. This allows the systems to exchange data and functionality, allowing them to work in unison. APIs are a collection of protocols, routines, and tools used to create software and applications.
Backend Developer Interview Questions
Backend development involves working on the server side of web applications, where the logic, database interactions, and server management take place. It focuses on handling data, processing requests from clients, and generating appropriate responses.
In this Top Backend Development interview questions, We cover Interview questions from all important topics from basic to advanced such as JavaScript, Node.js, Express.js, SQL, MongoDB, Django, PHP, Java Spring, and API. No matter whether you are a fresher or an experienced professional we have got questions that will enhance your skills and help you shine in your backend development interview.
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