The bCrypt project for Node started as a way to secure passwords. Before offerings like auth0 and Cognito were big, we were all still storing passwords in our own databases. Other platforms/languages had an implementation of bCrypt already. But, Node didn't have one yet. I wanted to learn more about how addons worked in Node and was building an app that needed logins so I decided to implement the bCrypt algorithm for Node.
After some time I was able to get a first pass working and, as they say, the rest is history. I was surprised by how fast it took off. I released the code and it filled a need in the community. A lot of people have contributed, helping the addon grow and stablize since those early days.