We are building the infrastructure powering the next generation of global crypto and stablecoin payments — connecting hundreds of millions of users across thousands of wallets and blockchain networks. Our on‑chain layer is foundational to everything we do, and we take its security and correctness seriously.
About the role
As a Senior Smart Contract Engineer, you will design, write, and audit the on‑chain contracts that sit at the heart of our payments network. You will work across multiple EVM‑compatible chains and beyond, ensuring our protocol logic is secure, gas‑efficient, and upgradeable where appropriate. This is a high‑stakes, high‑ownership role for engineers who hold security as a first principle and have the rigour to match.
What you'll do
* Design and implement smart contracts for payment routing, settlement, and escrow across multiple chains
* Own the full contract lifecycle — from specification and development through testing, deployment, and post‑launch monitoring
* Write comprehensive test suites using frameworks such as Foundry or Hardhat, including fuzz and invariant testing
* Conduct internal security reviews and work closely with external auditors ahead of deployments
* Develop and maintain upgrade and governance mechanisms that balance flexibility with on‑chain security
* Stay current with EVM developments, new opcodes, Layer 2 environments, and emerging cross‑chain standards
* Collaborate with backend and protocol engineers to ensure seamless integration between on‑chain and off‑chain systems
What we're looking for
* 4+ years of professional smart contract development experience, with production deployments on mainnet
* Deep expertise in Solidity; familiarity with Vyper or Rust (for Solana/CosmWasm) is a bonus
* Fluency with Foundry and/or Hardhat, including advanced testing patterns (fuzzing, invariant, formal verification)
* Strong understanding of EVM internals — storage layout, gas optimisation, call patterns, and common attack vectors
* Experience with proxy patterns, upgradeability, and multi‑sig governance frameworks
* Familiarity with cross‑chain messaging protocols (e.g. CCIP, LayerZero, Wormhole) and Layer 2 environments
* Security‑first mindset with practical experience identifying and mitigating common vulnerabilities (reentrancy, front‑running, oracle manipulation, etc.)
* Strong written communication — able to produce clear specifications, post‑mortems, and audit‑ready documentation
Nice to have
* Experience with formal verification tools (e.g. Certora, Halmos, or Echidna)
* Background in payments, DeFi protocols, or stablecoin infrastructure
* Prior work with external audit firms or a track record of responsible disclosure
* Contributions to open‑source smart contract libraries or EIPs
What we offer
* Competitive salary and equity package
* Fully remote and async‑friendly working culture
* Flexible working hours and generous time off
* Home office stipend and equipment budget
* Token allocations and exposure to the cutting edge of Web3
* High‑ownership role with real impact at global scale
#J-18808-Ljbffr