In 2017, a single Ethereum dApp became so popular it clogged the network, slowing all transaction processing almost to a halt. But at its peak, this dApp – Cryptokitties – had only ~14,000 users. First-generation blockchains like Ethereum are slow in part because every validating node must process every transaction.

Sharding allows the work of validating transactions to be broken up amongst many ‘shards’, each of which is validated by different nodes. This lets the work of validating transactions scale with the number of shards, making it easier for the network to handle large transaction throughput.

Sharding is a difficult engineering problem that has rarely been successfully implemented, and the NEAR team has previously built one of the only sharded databases in production at scale today (which is used by Uber, Goldman Sachs, and Comcast). For a better understanding of the NEAR sharding design called “Nightshade”, see the technical overview here.