The response times in your solutions can make a big difference to the usability of the application. This section provides information on how to monitor and manage response times in Lightning and Visualforce.
In Lightning, it is important to monitor the complexity of your component hierarchy. While it is good to componentized for reasons of separation of concerns, too much of it can result in a heavy component tree, and result in poor performance. Salesforce provides an excellent tool known as Lightning Inspector, which provides insight into your component hierarchy and the rendering times each component takes. You can download and install this from the Google Chrome Web store.
The following shows an example screenshot for the FormulaForce application:
You may also have noticed that LEX displays page size and response time in the header:
