Last year I introduced the My Change Log feature for Pro Plan users which allows you to see all the recent changes you have made to your LEGO Collection. This is a great help in keeping track of what you are doing and identifying any mistakes made. Now, I have expanded this feature to track more changes that weren't possible before and added an undo button for each change.
Over the last few months, I've been gradually enhancing the search pages. I think Rebrickable's search features were already the most powerful and easy to use you can find, but the new system is far easier to use on mobiles and for casual LEGO users who aren't as familiar with the catalog as most AFOLs.
The Rebrickable-hosted Premium MOCs feature was introduced in late 2017 when Mocplans shut down. There were thousands of LEGO fans who needed access to the building instructions they had purchased, so Rebrickable started hosting them. At the same time, it became possible to submit new MOCs using this hosting method. This is now our preferred way of hosting Premium MOCs (vs self-hosted where the designer has to serve the files and handle payments), and so I have spent a lot of time lately focusing on improvements to make it fully competitive with other digital sales platforms out there.