I've noticed a pattern among popular open-source authentication systems like Keycloak, Authelia, and Supertokens—they predominantly rely on technologies such as Go and Java, coupled with PostgreSQL. This raises the question: why choose these technologies over the more prevalent Node.js and MongoDB? I'm interested in understanding the rationale behind these architectural decisions. Are there specific advantages to using Go and Java for authentication systems? And why is PostgreSQL favored over MongoDB in this context?
I tried looking for a popular open-source authentication system which is written in node.js and uses mongodb database but I didn't find none.