Another transcript that may be of interest to this list. Carl Dong recently did an excellent short video explaining the libbitcoinkernel project in Bitcoin Core. The transcript is here:

As he explains in the video libbitcoinkernel is the latest attempt to extract the consensus engine out of Bitcoin Core. There are many motivations for doing this. Obviously disagreements between the consensus engines of nodes across the network can lead to catastrophic forks. This boundary between what is part of consensus and what is not has occasionally been blurred in the past and for the most security critical part of Bitcoin Core (and Bitcoin generally) this is clearly unacceptable. This is not a criticism of anyone in the past, unravelling Satoshi's spaghetti code and the entanglement between the consensus engine and the rest of the codebase has been a decade long task, requires extreme care and is by no means completed.

As well as leading to some consensus bugs in older versions of Bitcoin Core, the leaky consensus abstraction has made it difficult for alternative implementations to be built in other languages and with different RPCs etc without risking falling out of consensus with Bitcoin Core.

This is clearly an ambitious long term project but the first PR in the series was recently merged [1] and Carl explains his thinking on the future direction of this project in the video and on the linked issue.