fusion-io (i believe, but please verify online) uses a spinning drive for frequent writes and an ssd for frequent reads, with software deciding what goes where, lessening the write traffic to the ssd, and thus wear to it.
No, Fusion-io has nothing to do with spinning drives. They make PCI-e flash drives with an FPGA as the "controller" for the flash. There are multiple communication channels, so you can simultaneously read and write from the drives, and there are various tunings available to control how garbage collection works. They are the only "SSD" that doesn't hide all the flash behind any kind of legacy disk controller or group protocol like NVMe
I think what you're trying to describe is apple's fusion drive.