When working with applications, there are often various limitations or preferences about how to handle application deployments. The most common ones are as follows:
Copying the files through FTP (most difficult to proceed)
Deploying through rsync
Continuous Integration Deployment
Deployment tools
The most unreliable and error-prone method is, of course, the FTP deployment. Not only does it take a long time, but it also does not easily allow to automate the process, and usually, does not allow to easily rollback the changes.
Before the deployment, it is good to clear the cache and empty the log folders to avoid transferring the files that are not project related. Also, ensure that you are not overwriting the parameters.yml file when redeploying the code.
All the post-deployment stuff, such as database migrations or assets management, needs to be either done on the developer machine and transferred (assets) or done manually. Multiple server deployment is very time consuming...