Configure your own 15-inch Apple MacBook Pro (2015) at OWC
Amazon.com: MCE Technologies 1TB Internal SSD Flash Upgrade for MacBook Pro Retina (Mid 2012 - Early 2013) - Includes USB 3.0 Enclosure for Original Drive & Install Kit! : Electronics
How to Upgrade the SSD on a MacBook Pro Retina Early/Mid/Late 2013/2014/2015 - Replacement Tutorial - YouTube
Apple MacBook Pro (15-inch, 2015) review: Old-school MacBook Pro is good for the dongle averse - CNET
Amazon.com: OWC 1.0TB Aura Pro X2 Complete SSD Upgrade Solution with Tools & OWC Envoy Pro Enclosure Compatible with MacBook Air (Mid 2013-2017) and MacBook Pro (Retina, Late 2013 - Mid 2015) : Electronics
MacBook Pro (Retina, 13-inch, Early 2015) Upgrade to NVMe M.2 SSD - YouTube
Amazon.com: Odyson - 128GB SSD Replacement for MacBook Pro 13" Retina A1502, 15" A1398 (Late 2013, Mid 2014) : Electronics
Apple 15-inch MacBook Pro with Retina Display (mid-2015): Force Touch trackpad and faster SSD, but no Broadwell | ZDNet
MacBook Pro Retina (Mid 2012): SSD Replacement - YouTube
How to install an SSD on a 15-inch Retina MacBook Pro