在生产中使用MongoDB构建索引的时间和频率

I am about to deploy a web app using MongoDB as storage. The problem is, that locally I can build the indexes whenever I want (also done automatically) - but you shouldn't do that in production. Now switching to production I am not quite sure on when to build the indexes and how often. Should I do it every day? Should I do it once a week? My project is like a small social network - so let's say I will have about 100.000 users someday. Depending on the amount of data it could take hours or even days to build indexes.I am about to deploy a web app using MongoDB as