I am the only one manual tester in a team that develops a heavy single page application. Recently we have received a complain from our user, that the application is very slow, hangs and crashes every time when he's using it.
This is the first time I am dealing with this kind of situation. So far I've gathered the following clues.
- The information about user's environment has been collected (OS, browser version - latest chrome, win7)
- User has a slow internet. He claimed his speed is ~2MBPS.
- The problem seems to occur when the tab with an application has been idle for a long time.
- The problem also seems to be related to heavy content that he created.
However I have failed to reproduce the issue in the similar to what he has environment.
What could be the next steps for me to take as a tester?