Senior Smart Contract Engineer

Circle (NYSE: CRCL) is one of the world’s leading internet financial platform companies, building the foundation of a more open, global economy through digital assets, payment applications, and programmable blockchain infrastructure. Circle’s platform includes the world’s largest regulated stablecoin network anchored by USDC, Circle Payments Network for global money movement, and Arc, an enterprise-grade blockchain designed to become the Economic OS for the internet. Enterprises, financial institutions, and developers use Circle to power trusted, internet-scale financial innovation. Learn more at circle.com . What you’ll be part of: Circle is committed to visibility and stability in everything we do. As we grow as an organization, we're expanding into some of the world's strongest jurisdictions. Speed and efficiency are motivators for our success and our employees live by our company values : High Integrity, Future Forward, Multistakeholder, Mindful, and Driven by Excellence. We have built a flexible work environment where new ideas are encouraged and everyone is a stakeholder. What you’ll be responsible for:  We are looking for a Smart Contract Engineer to design, implement, test, and maintain production-grade smart contracts across multiple blockchain ecosystems. This role focuses primarily on EVM-based Solidity contracts and Solana programs written in Rust using the Anchor framework, while also building the backend services that power and integrate with those contracts. As a Smart Contracts Engineer, you’ll be responsible for building secure and efficient smart contracts that power Circle’s core protocols. You’ll also contribute to the supporting backend services that enable transaction orchestration, indexing, and monitoring (70% smart contract development and 30% backend development) . You will work closely with protocol, infrastructure, and security engineering teams to deliver high-assurance, auditable solutions that support scalable, blockchain-based services across ecosystems.

Design and implement production-grade smart contracts across EVM and/or Solana ecosystems using Solidity and Rust Develop backend services and integration layers that interface with deployed smart contracts and internal systems Research and apply industry-standard design patterns and emerging best practices in smart contract and distributed systems engineering Optimize smart contract performance, including gas efficiency, while enforcing strong security through secure architecture and defensive coding practices Build and maintain transaction orchestration flows, event listeners, and indexing services that bridge on-chain and off-chain components Test, deploy, and manage upgrades for smart contracts and backend services in production environments Partner with security teams on audits, threat modeling, remediation, and production monitoring to ensure reliability and operational excellence What you’ll bring to Circle:  Core Requirements: Proven experience designing and developing production-grade smart contracts in Solidity and/or Rust, with strong emphasis on security, gas optimization, and performance Deep understanding of blockchain architecture, EIP standards, decentralized systems, and on-chain execution models Strong knowledge of smart contract security principles and common vulnerability patterns (e.g., reentrancy, access control flaws, arithmetic errors) Experience with smart contract development and testing frameworks such as Foundry, Hardhat, or Anchor Working knowledge of backend development, particularly services that interact with blockchain networks (transaction submission, event processing, indexing) Experience integrating smart contracts with backend systems and off-chain infrastructure Experience designing and deploying production-grade, scalable cloud services in AWS, Google Cloud, Microsoft Azure, or similar environments Strong collaboration skills with the ability to work