Is there a methodology for integration testing Java applications?

Question

Java

There is a large Java Web application.
Integration tests are built using TestNG, Maven and its plugins (Failsafe + plugins for the database and running JBoss).
All testing is placed in a separate module and launched through maven, which deploys the environment (expands the databases, launches the server, deploys the application into it), after that the tests themselves work through TestNG.
The problem is that initially everything looked very structured and simple, but over time the tests grew, and now adding new tests is no longer such a pleasant and fast task, since the tests have many dependencies and various conditions for their execution. Everything rests on the fact that the application has a main business process, which is modeled by tests, this process runs like a red thread through all testing with different branches, and a different set of input data. Is there a good methodology or examples of how this approach can be simplified or structured? Thank you.

Answer 1

Don't write tests that depend on others. This is a bad practice.
Prepare and clean data for each test separately.