The backend is one of the most expensive graphs in the development phase of a mobile application. The desire to save is justified, especially when the idea of the application is not completely sure.
Store data on the client-side
In this case, the application will work even without the Internet, but will be deprived of interactivity, and new content will appear only with the new version of the application in the store.
Who is it suitable for? Distributors of static content that you don’t need to interact with. Imagine that you are a writer or publisher of a magazine, and promote new works or issues through an application where content is updated with each update. In addition to text, static content refers to photos, videos, games. At the same time, system functions such as payment will be available, and the user will have the opportunity to receive new content that is already in the application through an In-App Purchase.
Use serverless application architecture
Or, in other words, Serverless. 
This solution does not require any special knowledge for deployment and support, nor a tangible budget – all the support is taken over by the cloud service on which you will build the architecture. AWS, Azure, and Firebase have many opportunities for this.
Let’s consider Firebase and briefly tell what it is. This is a BaaS platform (Backend-as-a-Service, or backend as a service), which is primarily known as a NoSQL class cloud database, but also offers many other services right out of the box. They are configured through the platform interface, which does not require writing a single line of server code. The tutorials will show you how to make a simple chat, configure analytics or optimization based on user behavior, write your own scripts, and more. This is faster and cheaper than making a backend, and any developer, not just the backend, has the necessary competencies.
Work with Firebase on Live Typing projects
Notifications in the Yodel app are built on Firebase Notifications. Advantages: a free solution, there is no limit on the number of notifications sent, which are the main function of the application, convenient integration, and good flexibility with advanced targeting.
Use SaaS Services
The application has typical functions, the creation and support of which are very expensive and can burden the client with paperwork. Therefore, their development from scratch happens infrequently. One example of such a function is a payment, and the de facto standard is to use a payment gateway of some bank.
And this applies to the mass of other features of the application. Need chats or push notifications? They are cheaper to take a ready-made, in the form of SaaS (Software-as-a-Service, or software as a service). What is SaaS? As in the case of BaaS, this is a generic name for solutions that do not work on the user’s computer, but in the cloud, and are maintained by its provider; the user needs to pay a monthly fee if the software is paid. SaaS has a good API, good integration, ready-made libraries for different OS and devices. It remains only to take and connect them to your project. In the medium term, it is cheaper and more reliable than writing your platform.
