The Blockchain Trilemma is a fundamental thought experiment in blockchain. The trilemma covers three major issues that conflict with each other: Decentralization, Security, and Scalability. Bitcoin can process only 7 transactions per second, and Ethereum currently can only handle around 15 transactions per second. In contrast, Visa is now capable of handling more than 24,000. In order to increase its transaction speed and throughput without sacrificing decentralization or security, Ethereum is implementing various scaling solutions. These solutions include sharding and rollup technology. According to Vitalilk Buterin, co-founder of Ethereum, “rollups” offer a ~100x increase in throughput and “sharding” offers a ~64x increase, so rollups on top of sharding offer a ~6400x increase in throughput. The School of Scaling covers the concepts and innovations in Ethereum scalability, as well as guides to using these scalability solutions.