The tutorial covers how to install MongoDB 5 on Debian/Ubuntu, create a root CA and self-signed TLS/SSL certificates using mkcert, configure the MongoDB server to use these certificates, store the certificates in a secrets manager called Doppler, access the certificates using the Doppler CLI, and finally configure a MongoDB client to connect to the server using TLS/SSL mode. The tutorial assumes prior knowledge of how TLS/SSL certificates and the chain of trust work.