Joyride is building the first dedicated 0DTE options exchange for crypto traders. Derivatives are the single largest opportunity to bring traditional finance on-chain, with over $3.5 trillion in notional volume traded in the U.S. every day. Our architecture is hybrid: a central limit order book (CLOB) for low-latency execution, paired with a blockchain for transparent, non-custodial settlement.
The Team
You'll join a founding team that includes the founders and early contributors of Origin Protocol, where we've been building on Ethereum since 2017 and have scaled products to nine-figure TVL. Two of Joyride's cofounders are early advisors to Solana and have built multiple venture-backed companies acquired by Google, Yahoo, and Walmart.
The Challenge
Centralized exchanges are fast but require trust. On-chain exchanges are trustless but slow. We refuse to accept this tradeoff. Joyride centralizes execution for speed and decentralizes verification for trust. Making that seam airtight is the hard part.
- Self-Custody Without Compromise: Users keep the keys to their own funds and can withdraw without permission from the exchange operator, even if our servers go down. This can't come at the cost of execution speed or capital efficiency.
- Verifiable Execution: Every off-chain trade must be provably valid on-chain. The exchange operator cannot front-run, reorder, or fabricate trades. Cryptographic proofs link the off-chain matching engine to on-chain settlement without trusting the operator.
- Censorship Resistance: If the exchange goes dark, users must be able to reconstruct their account state from public data and withdraw their funds. No capital can ever be trapped.
- Security: DeFi protocols have lost billions of dollars to smart contract exploits, oracle manipulation, and bridge failures. Our on-chain systems must be designed defensively from day one.
As our Founding Protocol Engineer, you will own the trust and verification layer of Joyride's hybrid architecture. You'll work alongside our Founding Principal Engineer, who owns the matching engine and risk engine. Together, you will build an options exchange that combines the speed of a CEX with the safety guarantees of a DEX.
If you've spent time thinking about how to make off-chain execution verifiable on-chain and how to protect users from a malicious operator, keep reading.
Problems you'll work on:
- How do you prove to a Solana program that 50,000 off-chain trades were executed fairly, without exceeding compute unit limits?
- What Merkle tree structure lets users prove their balance against an on-chain state root while keeping proof sizes small enough for a single transaction?
- How do you build a forced withdrawal mechanism that works even when the exchange operator is adversarial or offline?
- How do you batch-publish trade history to a DA layer without leaking information that front-runners can exploit?
Your domain:
- Settlement & Custody: Users keep custody of their own funds while trading on Joyride. The exchange can lock collateral for risk management but can never take it. When trades settle, funds move based on cryptographic proof, not operator permission.
- Verifiable Execution: Our matching engine runs off-chain for speed. That means traders are trusting us not to cheat. Your job is to eliminate that trust requirement. Prove to the blockchain that every trade was executed fairly and that the operator can't front-run or manipulate the order book.
- Censorship-Resistant Recovery: If Joyride disappears tomorrow, every user must be able to independently prove what they own and withdraw it. Trade history must be publicly available and verifiable without our cooperation.
- Unilateral Exit: Users must be able to leave the system on their own terms, even if the exchange operator is malicious or offline. This is the ultimate safety guarantee and the hardest problem to get right.
- On-Chain Security: The on-chain systems hold real money. You're the first line of defense, threat-modeling the boundary between off-chain and on-chain and designing systems that are resilient by construction, not by audit.
Who you are:
- Protocol Engineer, Not App Developer: You've worked at the infrastructure layer of blockchains: client implementations, consensus protocols, p2p networking, or cryptographic systems. You understand how chains work under the hood, not just how to deploy contracts on them.
- Applied Cryptographer: You think in Merkle trees, digital signatures, and commitment schemes. You can evaluate whether a ZK proof system, a TEE-based attestation, or a simpler signature scheme is the right tool for a given trust boundary. You follow the research but you ship production code.
- Hybrid Architecture Thinker: You understand how other exchanges connect off-chain execution with on-chain settlement. You have opinions about their tradeoffs and can articulate what you'd do differently.
- Security-Minded: You think like an attacker. When you see a bridge between an off-chain server and an on-chain program, your first instinct is to enumerate the ways it can be broken.
- Builder: You write code every day. You're not looking to manage a team. You want to architect and build critical infrastructure yourself.
Requirements:
- 5+ years of systems engineering in Rust, C++, or Go
- Deep experience with Solana program development or equivalent blockchain runtime
- Strong applied cryptography: Merkle trees, digital signatures, hash-based commitments, proof systems
- Understanding of DeFi security: common exploit vectors, smart contract auditing patterns
- Experience with hybrid or L2 architectures: off-chain execution with on-chain verification/settlement
Bonus:
- Built or worked on a hybrid exchange where matching happens off-chain and settlement happens on-chain
- Worked on state verification, fraud proofs, validity proofs, or forced exit mechanisms for an L2 or rollup, including DA integrations
- Contributed to a blockchain client or protocol implementation
What we offer:
- Competitive salary and meaningful equity
- Remote-first
- Full autonomy over your domain
- Open-source friendly
