  The main problem faced by smart contract platforms is the amount of time and
computational power required to reach consensus. In a classical blockchain
model, each operation is in fact performed by each node, both to update the
status and to validate the results of the calculations performed by others. In
this short survey we sketch some state-of-the-art approaches to obtain an
efficient and scalable computation of smart contracts. Particular emphasis is
given to sharding, a promising method that allows parallelization and therefore
a more efficient management of the computational resources of the network.
