Stutern.com does not have different websites, it is one website: www.stutern.com
You were right about the two different interfaces, that was due to reasons @kananga and @Keny stated, A/B testing while we move to a newer interface.
The new interface is more than a new interface, it is actually a lot of reengineerng of our product for talents and employers. With this you can easily search for jobs down to specific locations like Ikeja, Lekki, Yaba and not just Lagos. Also, you can print a free beautiful looking CV from your profile. And for employers, they can search for candidates easily wrt specific skill sets verified via test.
I hope we have more than answered your questions