SQL query optimization is bare minimum requirement when working with queries. Need to look for Indexes, Execution plan etc. Few links that help to understand query optimization.
In the load balancer setup for windows Internet Information Services (IIS) if shared folder is used for files to upload and download create virtual directory under application folder with alias as Upload(whatever you prefer) and physical path as \\sharedfilefolder\files$\AppFiles\ where files is the shared folder on sharedfilefolder and AppFiles is subfolder in the files folder Have the same setup on each server and the application works fine with upload and download of files from load balancer URL.
Angular Bootstrap Modal is one of the best angular component available for angular 5. Though it's simple sometimes possible to miss reading the API documentation properly. Set backdrop to "static" to avoid closing on click. Example: const modalRef = this . modalService . open ( ItemModalContentComponent , { size: 'lg' , backdrop: 'static' }); Properties backdrop Whether a backdrop element should be created for a given modal (true by default). Alternatively, specify 'static' for a backdrop which doesn't close the modal on click. Type: boolean | "static"