The core functionality of Tempdb allows the user to create, clone and run full PostgreSQL clusters. When creating temporary clusters for test cases it will automatically boost PostgreSQL performance by disabling data integrity protection feature such as full page writes and fsync.
Tempdb is heavily inspired by tk0miya's testing.postgresql. I wanted something wasn't as tightly coupled to unittest as I almost always use pytest for my projects. Another key difference is that Tempdb uses Unix sockets instead of TCP which easier allows concurrent execution.