The thesis addresses the problem of scalability in decentralized blockchains in the context of the trade-off between transaction throughput and hardware requirements to participate in the network. Rollups are presented, that is technologies to verify on-chain blocks executed off-chain by minimizing the assumptions of trust. The variant of the Optimistic Rollups, in particular of Optimism and the use of invalidity proofs through interactive binary search and of the Validity Rollups, in particular of StarkNet, and the use of validity proofs through STARKs are discussed. Finally, the two solutions are compared on withdrawal time, on the cost of transactions and techniques to minimize it, on the possibility of applying the technology recursively, on compatibility with Ethereum and on the licenses used.