How Does Backend Web Development Actually Work?

TL;DR

Backend web development works by receiving requests from a front end, processing them on a server, reading or writing data in a database, and returning responses. A basic backend needs a programming language, framework, package manager, server, and database, while APIs, cloud services, load balancers, microservices, and external software services support more complex applications.

Transcript

Every website can be split up into two parts, the front end and the backend. The front end is all the visual stuff you see on the webpage and the backend is what saves and manages your data. For example, if you are on amazon.com, the backend would store your order history, your profile. It would load search results and much more. In this video, we'... Read More

Key Insights

• A backend is the part of a website that saves and manages data, loads information, and performs operations that are not directly visible on the webpage. Examples include storing profiles, maintaining order histories, loading search results, and managing product information.
• A server is a computer programmed to receive messages from other internet-connected computers. In a web application, the computer sending a message is the client, while the computer receiving and processing that message is the server.
• A backend programming language turns a computer into a server that can receive messages. Popular choices identified in the source include JavaScript with Node.js, Python, Ruby, and Java, each supported by frameworks and package management tools.
• A backend framework reduces the amount of code required to build and operate a server. The examples given are Express for JavaScript, Django for Python, Rails for Ruby, and Spring for Java.
• A package manager installs and manages reusable packages that handle common backend tasks such as calculations, database communication, login, and authentication. The named package managers are NPM for JavaScript, PIP for Python, Bundler for Ruby, and Maven for Java.
• A database is software used to store and manage application data, often running on a computer separate from the backend server. The backend must be configured to communicate with it, and the popular examples provided are MySQL, Postgres, and MongoDB.
• An API is the collection of request types and URL paths that a backend permits and knows how to handle. Requests outside that defined interface produce errors, while allowed requests can create, retrieve, update, or delete application data.
• Cloud computing lets companies rent virtual machines for backends and databases, add more instances when traffic increases, and distribute requests with a load balancer. Platform services can automate this infrastructure, while microservices divide large backends into smaller, focused codebases.

Questions & Answers

Q: How does backend web development work?

Backend web development works through a request-response cycle. A front end sends a request containing an action or data to a backend server. Backend code processes the request, communicates with a database when information must be saved or retrieved, and returns a response. For example, placing an order causes the backend to save it and return confirmation that it was created.

Q: What technologies are needed to build a basic backend?

A basic backend uses a backend programming language to create a server, a framework to reduce the amount of required server code, and a package manager to install reusable packages. It also uses a database to store and manage application data. The source states that most beginner projects can be built with a server and a database.

Q: What is the difference between a client and a server?

A client is the computer that sends a message across the internet, while a server is the computer that receives it. Computers cannot receive internet messages by default, so backend code must program a computer to act as a server. In the shopping example, the customer's computer is the client and Amazon's backend computer is the server.

Q: What is the request-response cycle in a web application?

The request-response cycle is the general communication pattern between a front end and a backend. The front end sends a request, the backend performs the required work, and the backend sends a response. An order request may cause the backend to save data, while a warehouse request may cause it to retrieve that order and return the information.

Q: What is a backend API?

A backend API is the list of request types and URL paths that a backend allows, along with the behavior assigned to each request. A POST request to an orders path can create an order, a GET request can retrieve order history, and a DELETE request can cancel an order. Requests not permitted by the API receive an error.

Q: What is a REST API and how does it name requests?

A REST API uses the REST naming convention, in which the request type has a specific meaning and the URL path identifies the relevant resource. POST means creating something, GET means retrieving something, and DELETE means deleting something. Therefore, a POST request to an orders path represents creating an order. REST is described as the most common API convention.

Q: How do cloud computing and load balancers support a backend?

Cloud computing allows a company to rent virtual machines instead of buying and maintaining physical computers. One virtual machine can run the backend and another can run the database. When traffic grows, multiple machines can run the same backend code. A load balancer placed in front of them distributes incoming requests evenly, and unnecessary machines can be shut off later.

Q: What are microservices, PaaS, and SaaS in backend development?

Microservices split a large backend into smaller, focused backends that may use different languages and databases. Platform as a service, or PaaS, lets developers upload backend code while the provider configures virtual machines and load balancing. Software as a service, or SaaS, provides an existing backend and API that applications can call instead of building a specialized service themselves.

Summary & Key Takeaways

• Backend systems manage website data and operations that users do not directly see. A front end sends a request to a server, where backend code processes it, communicates with a database when necessary, and returns a response. This request-response cycle supports actions such as creating orders and retrieving order histories.

• Backend development commonly combines a programming language, framework, package manager, and database. Frameworks reduce the code required to create servers, while packages provide reusable functionality for common tasks. Package managers install and manage those packages. MySQL, Postgres, and MongoDB are presented as popular options for storing and managing application data.

• Cloud computing lets companies rent virtual machines instead of purchasing physical computers. Multiple backend instances can handle increased traffic, while a load balancer distributes requests among them. Platform services automate infrastructure setup, and larger applications may use focused microservices or external software services that expose APIs for specialized backend functions.