Ex-Sushi CTO Joseph DeLong to Launch Onchain Limit Order Book DEX on Robinhood Chain

Joseph DeLong, the former CTO of SushiSwap who now runs stablecoin card startup Colossus, announced on July 24 that he will launch a decentralized exchange called Deepstate on Robinhood Chain next week. The exchange is designed as a fully onchain limit order book, a technically challenging architecture that remains rare on EVM-compatible chains. DeLong described the project as a side project that “outgrew nights and weekends,” but did not disclose trading pairs, fees, or a token.

Deepstate is slated to launch on Robinhood Chain, an Arbitrum-based L2 that went live on July 1. The network has already attracted major DeFi protocols including Uniswap, 1inch, and perpetuals partner Lighter. Robinhood Chain surpassed Base in daily active users on July 21, recording 323,969 addresses against Base’s 274,520.

DeLong published a whitepaper on GitHub dated June 29, authored by him, detailing the exchange’s architecture. The core innovation is a limit order book stored entirely in smart contract storage. Each order is packed into a single 32-byte word containing a price tick, quantity, a rounding-correction code, and a time-priority nonce. Orders are stored in a binary radix tree keyed by price and arrival order.

The design offers 4.3 billion logarithmically spaced price ticks and caps the work each trade performs at the tree’s fixed 64-bit depth. This is intended to keep gas costs bounded regardless of the number of resting orders on the book. In a typical EVM environment, fully onchain order books are expensive because every storage read and write costs gas. Most DEXs that use order books match trades offchain and settle onchain, while automated market makers (AMMs) avoid matching altogether.

Deepstate’s core construction is credited to Warp, a matching engine design presented by Plasma co-author Joseph Poon and Christopher Jeffrey at EthCC in 2023.

DeLong served as SushiSwap’s CTO until his resignation in December 2021. He later argued that DAOs need hierarchy in an ETHDenver postmortem on his time at Sushi. After SushiSwap, he founded NFT lending protocol Astaria and held a senior director role at Kraken. Today he is CEO of Colossus, a startup building a stablecoin credit card network designed to bypass Visa and Mastercard. Deepstate is separate from Colossus; DeLong described it as a side project that evolved beyond a hobby.

Robinhood Chain launched its public mainnet on July 1 with Uniswap, 1inch, Arcus, and perpetuals partner Lighter already live. Lighter has since made Robinhood’s stock tokens eligible collateral for its perps markets. Deepstate would enter a crowded field, but its fully onchain limit order book design is distinct from the AMMs and hybrid models currently on the network. The chain’s rapid user growth suggests demand for DeFi services, though whether users will adopt a gas-intensive order book remains to be seen.

DeLong gave no specific launch date beyond “next week” and did not name trading pairs, fee structures, or a token. The whitepaper does not mention a governance token or revenue sharing. No smart contract addresses or testnet deployment have been shared publicly. Readers should treat the announcement as a development update rather than a confirmed product launch. The exchange’s performance and security will depend on audited code and real-world usage, neither of which has been presented yet.

For users interested in trading on Robinhood Chain, Deepstate offers a novel order book model that could provide tighter spreads and more precise price control than AMMs, if the gas costs are manageable. However, the lack of audited code, fee schedule, or verified test results means the project is still in a pre-launch phase. Users should not deposit funds or grant approvals to any contract claiming to be Deepstate until official addresses are confirmed through DeLong’s verified channels. The announcement is a signal of development activity, not a call to action.

Source: The Defiant, “Ex-Sushi CTO Joseph DeLong to Launch Order Book DEX on Robinhood Chain,” July 24, 2026. https://thedefiant.io/news/defi/ex-sushi-cto-joseph-delong-to-launch-order-book-dex-on-robinhood-chain