There are various optimization and checks you can do for performance in DXA
- Enable DD4T caching.
<add key="CacheSettings_CallBackInterval" value="30" /> <add key="DD4T.CacheSettings.Page" value="3600" /> <add key="DD4T.CacheSettings.Component" value="3600" />
- Outputcaching as you mentiondmentioned.
- Make sure your binaries css, images, and js are getting cached(max age) in browser, it could be a big performance impact as each binaries request also go to your code which do some validation before serving the binary. we recently faced issue because of this.
- Make your code CDN ready with cache-control:public for the binaries, it will help when you get the code at production. CDN/Akamai is very much required on production.