Ok let's clear this up for people who think the SSD in the Retina MacBook Pro is "soldered on" and therefore not upgradeable : r/apple
Amazon.com: INDMEM PCIe NVMe Gen3x4 SSD 1TB 3D TLC NAND Flash Hard Drive SSD Replacement for MacBook Air 2013-2017, MacBook Pro Retina 2013-2015, iMac 2013-2017, Mac Pro 2013, Mac Mini 2014 (1TB) : Electronics
Easy-to-Use Guide to MacBook Pro Hard Drive Replacement – Appleparts.io
MacBook Pro 15" Unibody Late 2011 Hard Drive Replacement - iFixit Repair Guide
MacBook Pro (Retina, 13-inch, Early 2015) Upgrade to NVMe M.2 SSD - YouTube
How to Upgrade Macbook Pro SSD Hard Drive 2017, 2016 A1708 - YouTube
Replace your 2009-2012 MacBook Pro HD with an SSD
Easy-to-Use Guide to MacBook Pro Hard Drive Replacement – Appleparts.io