Due to the fact that I am a complete novice when it comes to the tech involved, I typically avoid making comments on these types of posts. First of all I want to compliment you on how this was presented. Although I would be lying if I said I understood every detail, I understood quite a bit of this post (great job explaining it to a layman!).  

It gives the impression that significant progress is being made in one of the (if not the) biggest areas of need... scalability. Thank you for including the names of huge recognizable companies using RocksDB. Even if I don't fully understand it, knowing that sites with a huge user base use it makes me excited that we are planning to have a similar (or even bigger) user base. 

It also seems that there has been significant progress on SMTs. Including the details of the significant changes was a great idea. 

My favorite piece is the revelation that HF 20 is being pushed to the forefront again. That signals to me that significant progress has been made in many other areas that will allow manpower and resources to be spent on it. 

I can't wait for the launch of these so that we can use them to help the community to grow and thrive.