"Many details of how Ethereum 2.0 will work are available today, and multiple teams are already working on implementations of it. One large component for which neither spec nor any detailed info is available today is the shard chains."
When Lightning STARKs (article)
On Efficient Ethereum Storage (article)
An Elegant Relationship (DAI, ETH, MKR) (article)
How Ethereum can scale with SNARKs 101 (article)