In my earlier posts about building a custom Raspberry Pi SATA NAS, and supercharging it with 2.5G networking and OMV, I noted that my builds were experimental only—they were a mess of cables and parts, with a hilariously-oversized 700W PC power supply.
I lamented the fact there was no simple "SATA backplane on a board" for the Raspberry Pi Compute Module 4. But no longer.
Wiretrustee's SATA Board integrates a SATA controller and data and power for up to four SATA drives with a Raspberry Pi Compute Module 4.
And their entire solution makes for a great little Raspberry Pi-based NAS, using software like OpenMediaVault.