Scalability has always been an issue for public ledgers, this is old news. It’s a problem that engineers have been trying to solve for a number of years now. The issue has become more of a pressing need in the last 12 months with an increase of activity on public ledgers, and this has been reflected in transaction fees, sometimes seeing over $40 USD for common contract interactions on Ethereum. The two main approaches to solving this issue have been a) scaling at the base layer, using techniques like sharding and novel consensus protocols, and b) layer 2 scaling techniques. Both approaches have been successful in different ways. Read more.