Performance of the job can be improved if:

1) Unnecessary column are removed from the up and down stream links.
2) Removing these unnecessary columns will help reducing the memory consumption.
3) Always specify the list of columns in the select statement when reading from database. This will not bring unnecessary column data in the job which will save memory and network consumption.
4) Use RCP very carefully.
5) Understand the data-type before using them in the job. Do the data profiling before bringing data in the job.