Senior Software Engineer - Special Projects
Circle, a pioneering financial technology company, is at the forefront of revolutionizing the movement of digital value across the globe efficiently and affordably. With a focus on modernizing payment systems through blockchain technology, particularly USDC, Circle enables businesses, institutions, and developers to leverage these advancements for economic growth and financial inclusion.
Overview:
At Circle, a culture of transparency and innovation underpins our remote workplace where teamwork and adaptability are key to success. Embracing core company values such as mindfulness and integrity, employees contribute to an environment that fosters collaboration and welcomes fresh ideas and diverse perspectives.
Key Responsibilities:
Seeking a skilled Smart Contract Engineer to join the USDC Smart Contract team at Circle, you will lead the development and scalability of smart contracts across multiple blockchain ecosystems. Responsibilities include designing, coding, testing, and deploying secure smart contracts while enhancing existing solutions for improved efficiency and safety. Implementing security practices and performance optimization methods is crucial, along with conducting risk assessments and devising strategies to enhance security on various blockchain platforms.
Requirements for Candidates:
Senior Software Engineer (III) Requirements:
Over 4 years of software development experience, inclusive of internships.
Demonstrated expertise in smart contract development on blockchain platforms for a minimum of 2 years.
Proficiency in programming languages like Rust, Go, or others commonly used for non-EVM smart contracts.
Experience with non-EVM blockchain ecosystems such as Cosmos or Solana.
Strong background in architecting, coding, testing, and deploying secure smart contracts.
Emphasis on security best practices and implementing measures to enhance security in smart contract development.
Up-to-date knowledge of trends and technologies in blockchain development.
Staff Software Engineer (IV) Requirements:
Over 7 years of software development experience, with a minimum of 4 years in smart contract development on blockchain platforms.
Proficiency in non-EVM programming languages and related tech stacks.
Deep understanding of various blockchain protocols and principles.
Ability to lead technical teams, mentor junior engineers, and collaborate effectively across departments.
Strong communication skills to facilitate collaboration and consensus building among team members and stakeholders.
Additional Info:
Eligible for day-one PERM sponsorship for qualified candidates. Flexible compensation ranges consider factors such as experience, qualifications, and business needs, with added benefits like equity, discretionary vacation, health benefits, and more.
Equal Opportunity Employer Statement:
Circle values diversity and promotes an inclusive workplace where all are welcome, without discrimination based on race, religion, nationality, gender, age, or disability status. Participating in the E-Verify Program when required by law reinforces our commitment to legal compliance and a fair work environment.
Mobile Developer
We are looking for a Mobile Developer to help build and optimize the mobile experience for the platform. You will work closely with our product, backend, and design teams to create a performant, secure, and intuitive mobile app that supports real-time 3D property viewing, blockchain interactions, and AI-powered recommendations.
Responsibilities :
Develop and maintain cross-platform mobile applications (iOS and Android)
Integrate with backend APIs and smart contracts (Web3)
Optimize app performance, responsiveness, and security
Collaborate with UI/UX designers to implement immersive and intuitive experiences
Integrate 3D content using tools like Unity, Babylon.js, or Three.js (if mobile-compatible)
Enable wallet connections (e.g., WalletConnect)
Implement features such as property listings, profiles, payments, notifications, etc.
Conduct testing and debugging across multiple devices and OS versions
Participate in code reviews and Agile sprints
Requirements :
5+ years of mobile development experience
Strong proficiency with React Native (preferred) or Flutter
Experience integrating RESTful APIs and Web3 tools (e.g., Ethers.js, WalletConnect)
Familiarity with blockchain wallets and decentralized identity concepts
Basic understanding of React and front-end development
Experience with Firebase, Push Notifications, and payment SDKs
Ability to work with 3D content or ARKit/ARCore is a plus
Experience publishing and maintaining apps in App Store and Google Play
Strong problem-solving and debugging skills
Excellent communication and collaboration in a remote team environment
AI/ML Engineer
We are looking for an experienced AI/ML Engineer to join our team and drive the development of intelligent systems that enhance user personalization, property recommendations, pricing models, and more. You will work across disciplines with frontend, backend, and blockchain engineers to create and deploy real-world AI features in a decentralized ecosystem.
Responsibilities :
Build and deploy machine learning models for property recommendations, price prediction, and user engagement optimization.
Integrate LightFM, LangChain, and OpenAI/LLM frameworks.
Design AI-powered agents, chatbots, and virtual assistants.
Collaborate on feature engineering, data pipelines, and AI service APIs.
Work with frontend developers to display predictive results and recommendations in the UI.
Deploy models using AWS SageMaker or similar infrastructure.
Monitor model performance and continuously improve accuracy and efficiency.
Stay up to date with advancements in GenAI, real estate AI, and MLOps best practices.
Requirements :
5+ years of hands-on AI/ML development experience.
Strong Python skills with frameworks like NumPy, Pandas, Scikit-learn, TensorFlow, or PyTorch.
Experience with recommender systems (e.g., LightFM), NLP, or conversational AI (LangChain).
Familiar with deploying models in cloud environments (preferably AWS SageMaker).
Working knowledge of React and frontend integration basics.
Solid understanding of data preparation, model tuning, and deployment workflows.
Strong problem-solving ability and self-management skills.
Smart Contract & Web3 Developer
We are looking for an experienced Smart Contract & Web3 Developer to join our team. This role is central to the design, development, and deployment of secure and scalable blockchain-based solutions. You will work closely with frontend and backend developers, designers, and product managers to integrate smart contracts into a seamless and immersive user experience for real estate investment and trading.
Responsibilities :
Design, develop, and deploy secure smart contracts on Ethereum or compatible EVM chains (e.g., Polygon).
Build and test tokenization logic for real estate assets using NFTs and ERC standards (e.g., ERC-721, ERC-1155).
Integrate Web3.js/Ethers.js with the frontend (React) and backend services.
Collaborate with designers and frontend developers to enable blockchain-powered UX flows (e.g., wallet login, transactions).
Implement features such as fractional ownership, DAO voting, and rental agreements.
Write unit tests and perform contract audits to ensure security and efficiency.
Manage smart contract deployments and monitor their on-chain performance.
Stay updated on Web3 trends, L2 solutions, and relevant protocols that can enhance the platform.
Requirements :
3-5 years of experience in smart contract development and blockchain technology.
Strong knowledge of Solidity and smart contract best practices.
Familiarity with Ethereum, Polygon, or other EVM-compatible chains.
Experience with Web3 libraries (Web3.js, Ethers.js) and frontend integration.
Basic understanding of frontend development using React and TypeScript.
Experience deploying contracts using tools like Hardhat or Foundry.
Understanding of decentralized storage solutions like IPFS.
Comfort with using blockchain APIs (Alchemy, Infura) and node management.
Good communication skills and ability to collaborate in a cross-functional team.
Engineering Manager
We are looking for an Engineering Manager to lead our distributed engineering team. In this role, you will guide a cross-functional team of developers (frontend, backend, Web3, AI/ML, mobile, QA), ensuring technical excellence, timely delivery, and alignment with product goals. The Engineering Manager will serve as both a technical leader and a people manager, fostering innovation and accountability across the team
Responsibilities :
Lead and manage a team of software engineers (frontend, backend, Web3, AI/ML, mobile, QA)
Define and maintain engineering best practices, coding standards, and architecture guidelines
Collaborate with Product Managers and Project Managers to plan and prioritize sprints
Drive the execution of technical projects from design through delivery
Conduct code reviews, mentoring, and skill development for engineers
Ensure scalable, secure, and high-performance systems across the stack
Oversee DevOps practices, CI/CD, and cloud deployments (AWS, Docker, Terraform)
Coordinate with Web3 developers for smart contract integration and audits
Monitor and improve system reliability, performance, and security
Manage hiring, onboarding, and performance evaluations of engineering team members
Requirements :
5+ years of experience as a Software Engineer / Full Stack Developer
2+ years of proven leadership experience as an Engineering Manager / Tech Lead
Strong technical background in React, Node.js, Python/FastAPI, Web3 (Solidity/Ethers.js)
Familiarity with cloud infrastructure (AWS, Docker, Terraform)
Experience with Agile/Scrum methodologies and sprint planning
Excellent problem-solving, communication, and organizational skills
Ability to manage a remote, distributed engineering team effectively
Basic understanding of front-end development (React/JS) is required
Smart Contract Developer
We’re looking for an experienced Smart Contract Developer to join our remote team. You’ll be responsible for designing, developing, and deploying secure and efficient smart contracts for blockchain-based applications. The role involves close collaboration with other developers and product leads to bring new ideas to life.
Key Responsibilities:
- Design, write, and test smart contracts (Solidity)
- Review and optimize existing contracts for gas efficiency and security
- Integrate contracts with front-end or backend services via Web3
- Participate in code reviews, audits, and documentation
- Stay current with blockchain trends and best practices
Requirements:
- Proven experience with Solidity, EVM-based blockchains, and related frameworks (Hardhat, Truffle, Foundry, etc.)
- Good understanding of DeFi protocols, NFT standards (ERC-721/1155), or Layer-2 solutions
- Familiarity with smart contract security and testing methodologies
- Experience using GitLab, Git, and version control workflows
- Ability to work independently and communicate effectively in English
Nice to Have:
- Background in cryptography, auditing, or backend development
- Contributions to open-source blockchain projects
What We Offer:
- Fully remote and flexible working hours (team across EST, CET, GMT+2)
- Flexible payment options — including crypto payments (USDT, USDC) or traditional methods
- Collaborative and friendly international team
- Opportunities to grow into lead or architecture roles