Comment by Reinmar

I feel we were quite lucky back in 2015 when we started rewriting CKEditor with RTC as a core requirement. At the time, OT seemed like the only viable option, so the choice was simple :)

What definitely helped too was having a very specific use case (rich-text editing) which guided many of our decisions. We focused heavily on getting the user experience right for common editing scenarios. And I fully agree that it's not just about conflict resolution, but also things like preserving position mappings. All these mechanisms need to work together for the experience to make sense to the end user.

This is an older piece (from 2018), but we shared more details about our approach here: https://ckeditor.com/blog/lessons-learned-from-creating-a-ri...

One clear issue with OT that we still face today is its complexity. It's nearly 8 years since we launched it, and we still occasionally run into bugs in OT – even though it sits at the very core of our engine. I remember seeing a similar comment from the Google Docs team :D