dYdX is a L2 DEX that currently supports perpetual trading. dYdX runs on smart contracts on the Ethereum, and allows users to trade with no intermediaries. It was founded in 2019 by Antonio Juliano and launched in 2020.
Trades are settled in an L2 (layer-2) system, which publishes ZK (zero-knowledge) proofs periodically to an Ethereum smart contract in order to prove that state transitions within L2 are valid. Funds must be deposited to the Ethereum smart contract before they can be used to trade on dYdX.
By settling trades on L2, the exchange is able to offer much higher trade throughput and lower minimum order sizes, compared with systems settling trades directly on Ethereum. This is achieved while maintaining decentralization, and the exchange is fully non-custodial.
The L2 system was developed with, and is operated jointly with, Starkware.