There are various kinds of attack that can be made on any kind of application, as they depend on loopholes in the application. Still, applications can do a lot to prevent these attacks.
Let's see a few of the most common non-vulnerability-based attacks and how to prevent them.
A denial-of-service (DoS) attack is an attempt to make a server machine unavailable to its intended users temporarily. An attacker uses one or many machines to make continuous requests to the server to take it down.
The best way to prevent DoS is to use an external service such as CloudFlare, which uses a lot of different techniques and data from various sources to block malicious requests on your server. It's always better to avoid handling DoS on your server and leave it to a service created by DoS experts.