Staff Protocol Engineer - Cashen

Cashen is the institutional deal execution layer on Canton Network, backed by Ergonia. We connect whitelisted institutional counterparties for collateralized crypto lending and CC locking arrangements using a tri-party custody model. Cashen operates as a ministerial agent — we never hold assets or take principal risk. We have an operational mainnet validator, a live off-chain marketplace, and active counterparty relationships with institutional participants. The on-chain protocol layer is entering active development now.

The Role

This is a protocol ownership position. You will own the full DAML smart contract surface of an institutional financial protocol: from on-chain deal settlement and locking contracts, through collateral lifecycle enforcement, yield attribution and Canton ecosystem integration. You work directly with the Head of Engineering on system architecture and backend integration.

You will be making architecture decisions that define the protocol — what the blockchain enforces versus what the backend handles, how deal templates are abstracted across modules, and how settlement flows guarantee correctness for institutional capital. The three pillars below define what we need.

Responsibilities:

DAML Smart Contract Architecture

• Design and implement DAML contracts for token locking settlement: loan lifecycle, recall and substitution mechanics, interest accrual, breach enforcement, and unbonding flows
• Build DAML contracts for a collateralized lending module: collateral posting, CIP-56 atomic settlement, LTV monitoring triggers, margin call enforcement, loan state machine
• Define the deal abstraction layer: base Deal template that modules extend, or separate templates with shared backend abstraction
• Own on-chain correctness guarantees: type safety, state machine completeness, guard conditions, and audit trails for institutional-grade financial workflows
• Collaborate with Canton Foundation on CIP and network-level integration

On-Chain / Off-Chain Boundary Design

• Determine which deal states, transitions, and enforcement logic belong in DAML contracts versus the NodeJS backend
• Design the integration layer between on-chain contracts and backend services: how the backend reads on-chain state and triggers DAML contract actions
• Design Canton wallet integration for institutional participants

Financial Protocol Engineering

• Implement settlement flows, yield attribution, and interest accrual logic with per-round precision
• Integrate with custodian APIs for collateral lock/release/liquidation instructions
• Integrate with price oracles for LTV price feeds with circuit breakers and staleness checks
• Ensure correctness guarantees throughout: idempotency, immutable state history, and reconciliation between on-chain and off-chain state

• 5+ years in smart contract engineering, protocol development, or backend engineering for financial systems
• Strong DAML language experience.  Canton deployment experience is a strong plus.
• Production smart contract experience on any chain (Canton, EVM, Solana).  Borrow/Lend protocol experience is a strong plus.
• TypeScript proficiency — the backend is NodeJS and you will work closely with the backend layer for on-chain/off-chain integration
• Comfortable making architecture calls with real financial consequences, not just optimizing gas costs
• Passionate about building from zero to one. You thrive in early-stage environments where speed, ownership, and resourcefulness matter more than process and hierarchy

• Protocol ownership from day one: You define the on-chain architecture for an institutional financial protocol on Canton Network, the enterprise-grade distributed ledger
• Real and operational: Live mainnet validator, operating marketplace, active counterparty relationships — this is not a whiteboard project
• Canton ecosystem: Backed by Ergonia with access to Canton ecosystem resources and partners
• Institutional demand: Counterparties are ready. You are building for real users with real capital
• Lean team, high leverage, fast paced environment: Every architectural decision you make defines the protocol
• Competitive salary and benefits
• Equity with long-term upside aligned to the success of Cashen.