What is a backend and when is it needed
Mobile applications can be roughly divided into those that do not send requests to the remote database, and those that do. The first group includes applications such as timers, alarms, sticker packs, some games and photo editors. The second group includes applications in which you need to at least register users and store their first name, last name and phone number. To store this data, you need a separate place, and this place is called the server part, or backend, and mobile development of such an application is carried out using a client-server architecture.
The front end is a mobile application that shows the user interface and functions to achieve custom goals. If we take an online store application as an example, then through it the user interacts with products, search and filters, sends products to the cart and makes a purchase.
The server part (backend) is a computer with a data processing program running on it. Like a mobile application, this program is also a code and it also needs to be programmed. An online store application, such as those developed by Live Typing ILE DE BEAUTE or Sephora, cannot exist without a backend responsible for presenting product data, accounting, ordering and making payments.
A good backend has:
flexibility that allows backend developers to add new features without problems and crutches and thereby develop the application;
scalability;
active technical support, capable of giving a quick answer to a question, quickly fixing an error, making the necessary change in the interests of the product.
The user does not see the backend, but their role is important. This is an independent part of your product that you need to invest in. And if you do not understand the backend as a separate product, then it will depreciate to just one API documentation.
What is API
API (Application Programming Interface) is a part of the backend that plays the role of a communication language between the server and the client (in our case, with a mobile application). The API is used to present server data in a format that is convenient for this communication.
When we say “API of a mobile application” we mean not only the data presentation format, but the application that takes the data, processes it and gives it to the client in this format. When we say “writing an API,” it means that we are programming business logic, writing a document, and inventing the formats ourselves.
A good API is characterized by:
adherence to the general principles of development,
current and complete documentation,
stability of work,
fast response time to a request from a client,
versioning.
It so happens that the business logic is well written, but the API is bad. For API design and programming, it is important to have specific knowledge: to know standard approaches and best practices, to understand how mobile applications work, to know the needs of their users.