A customer sells mongodb wrapped into its binary, on premises, to thousands of users. It's a software built on top of Mongodb.

Thousands of their on premises customers use a single node replica set. MongoDB has been telling them to change this to a 3 node replica set architecture for a long time, however it comes with too much logistical cost and operational risks to be done in the short term. Additionally, when they perform certificate rotations, they also rotate the password for their private key. This is a non-negotiable security requirement for them.

Currently, performing certificate password rotations online is not supported, even though rotating the certificates themselves is. They currently have to restart their server to rotate these certificates. Because of this, rotating a tls certificate password translates into ~1.5 business weeks' worth of downtime per year for their customers and ~5.4 weeks per year operational effort from them. This is documented in this AHA https://mongodb-sfdc.ideas.aha.io/ideas/FF-I-9993