In large companies with multiple teams working in parallel, it is very common to end up having tons of integration conflicts. This occurs more frequently when the codebase is under heavy development.
In order to mitigate this, it is highly recommended to use CI. The main idea is that development branches should not diverge much from the master branch. One way to do it is splitting the changes or new features into really small chunks so they can be finished and merged back pretty fast. Another way is to merge regularly; this is more suitable when features are difficult to break down into small ones.
When facing indivisible features, such as architectural changes, Feature Toggles are very helpful. With Feature ...
