Lightning Components run at the client-side, in a single page (where they are created and destroyed as needed), and alongside other components that work on the same data. In this blog post, we discuss how these characteristics impact performance, and review a list of best practices to optimize the performance of your Lightning Components.
https://developer.salesforce.com/blogs/developer-relations/2017/04/lightning-components-performance-best-practices.html
https://developer.salesforce.com/blogs/developer-relations/2017/04/lightning-components-performance-best-practices.html