Won't be answering quora like questions in hashnode 🤓

Agreed back up is a must for any db. How about delayed secondaries in mongo (https://docs.mongodb.org/v3.0/tutorial/configure-a-delayed-replica-set-member/). What is the use case of this?

mongodump is not a recommend way if your data size is huge say >100 gb. It takes a long time to backup and to restore even more. Best way is to take file system snap shot. Refer this guide - https://docs.mongodb.org/v3.0/tutorial/backup-with-filesystem-snapshots/ For sharded cluster refer this guide - https://docs.mongodb.org/v3.0/tutorial/backup-sharded-cluster-with-filesystem-snapshots/ We use https://www.mongodb.com/cloud is a service from MongoDB inc which provides backup, automation and monitoring.