Does the Synology DS1623xs+ support 10GbE expansion?

Regarding the Synology: Out of the box it gives you four 1GbE RJ-45 ports, but the real story is the optional 10GbE SFP+ slots via an add-on card. That SFP+ upgrade path means you’re not stuck with Gigabit forever — you can bump up to 10GbE when your infrastructure catches up.