There are two different ways how to manage the application settings if you use VSTS and Azure. Please keep in mind this is only an example of tools used for continuous deployment.
You can override JSON files(Web config in older systems) in the CD pipeline in VSTS or you can override the settings in Azure ‘Application Setting’ section. I’m just thinking what setting should be managed where? My idea is to manage settings which depend on 3rd party modules like databases (connection strings), external services (e.g. Application Insights) in the Azure Application Settings section. This can give you the flexibility to change some setting very quickly if some changes appear in the 3rd party system.
The stuff which depends only on the app I would manage in the VSTS. What about feature toggles? Let’s say you have a stock Market and you are building a module which manages selling/buying new cryptocurrency called Blah. After all the tests you decide to make a release of the feature and take of the flag which is responsible to enable/disable the new feature. Where would you take off the flag- in App Settings in Azure or in the CD pipeline in the VSTS?
Maybe there are more other types of settings which I didn’t mention, and which are problematic to manage? The main reason I am asking this question is the settings management becomes problematic when the application growths, it is very easy to cause a mess in the config files. Please tell me what is the proper way of management of the app settings in the Web Application?