Senior Software Engineer - Special Projects
Status
Los Angeles, USA
Full time
Remote
Compensation is not specified
Role
Software Engineer
Description
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.
Skills Required
Circle
Website
www.circle.comCompany size
Not specified
Location
United States
Description
Not specified
Status
David Rutkovsky
Chief Technology Officer (CTO) / Senior Full-Stack Developer (Web3)
London, UK
London, UK
Full time
Remote
About the Role
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
Payment in Crypto
Merklio
ZK-Infrastructure Engineer
Hong Kong
Hong Kong
Full time
Remote
Merklio is developing a private order-book aggregator using zero-knowledge proofs. We need a ZK-Infrastructure Engineer to build our proof generation pipeline and optimize proving times for complex circuits.
Expectations:
Design and implement circuits for merkle membership and signature aggregation
Optimize witness generation and prover memory usage
Build a distributed prover system with load balancing
Reduce proving time from 30s to <5s using GPU acceleration
Collaborate with researchers on new polynomial commitment schemes
Write performance benchmarks and regression tests
Deploy provers as microservices on Kubernetes
Maintain a devnet for testing with real transaction data
Contribute to open-source ZK libraries (e.g., gnark, arkworks)
Nice to have:
Experience with MPC (multi-party computation)
Knowledge of TLSNotary or ZKEmail
Published papers or talks at ZK conferences
Chinese+English language proficiency
Expectations:
Design and implement circuits for merkle membership and signature aggregation
Optimize witness generation and prover memory usage
Build a distributed prover system with load balancing
Reduce proving time from 30s to <5s using GPU acceleration
Collaborate with researchers on new polynomial commitment schemes
Write performance benchmarks and regression tests
Deploy provers as microservices on Kubernetes
Maintain a devnet for testing with real transaction data
Contribute to open-source ZK libraries (e.g., gnark, arkworks)
Nice to have:
Experience with MPC (multi-party computation)
Knowledge of TLSNotary or ZKEmail
Published papers or talks at ZK conferences
Chinese+English language proficiency
Payment in Crypto
Merklio
Smart Contract Engineer (Solidity / Rust)
Hong Kong
Hong Kong
Full time
Remote
Merklio is building a modular settlement layer for institutional staking. We are looking for a Smart Contract Engineer who will own the core vault contracts, liquid staking tokens, and reward distribution mechanisms.
Expectations:
Design and deploy upgradeable proxy contracts (UUPS)
Write high-assurance tests with invariant testing (Foundry)
Implement access control (Ownable2Step, roles)
Integrate with Chainlink Automation and CCIP
Write Natspec docs and deployment scripts
Participate in internal security reviews and bug bounties
Optimize storage layouts to reduce gas costs by >15%
Collaborate with the research team on novel staking mechanisms
Nice to have:
Experience with LayerZero or Hyperlane
Published audit reports or contest wins (Code4rena / Sherlock)
Knowledge of ZK-proofs (basic)
Chinese language proficiency
Expectations:
Design and deploy upgradeable proxy contracts (UUPS)
Write high-assurance tests with invariant testing (Foundry)
Implement access control (Ownable2Step, roles)
Integrate with Chainlink Automation and CCIP
Write Natspec docs and deployment scripts
Participate in internal security reviews and bug bounties
Optimize storage layouts to reduce gas costs by >15%
Collaborate with the research team on novel staking mechanisms
Nice to have:
Experience with LayerZero or Hyperlane
Published audit reports or contest wins (Code4rena / Sherlock)
Knowledge of ZK-proofs (basic)
Chinese language proficiency
Payment in Crypto
Klein Labs
Director of BD & Strategic Partnerships
Singapore +2
Singapore +2
Full time
Hybrid
We are looking for a commercially driven and strategically minded leader to take ownership of Klein Labs’ global business growth and external partnerships. This role will cover several core business lines, including market-making services, OTC, treasury solutions, ventures, and fundraising coordination.
You will work closely with the founding team to develop and execute global BD and fundraising strategies, expand and maintain relationships with projects, exchanges, funds, family offices, high-net-worth individuals, and other key ecosystem participants, and continuously drive business partnerships, capital introduction, and long-term strategic value creation. This role is ideal for someone with strong execution, mature business judgment, and a solid understanding of capital markets, who can thrive in a fast-paced, high-autonomy, crypto-native environment.
Responsibilities
Develop and execute business development, strategic partnership, and fundraising plans across Klein Labs’ business lines, driving revenue growth, partnership conversion, and capital introduction.
Build and maintain long-term relationships with exchanges, projects, DAOs, market makers, funds, family offices, HNWIs, and other key ecosystem participants.
Design and implement partnership models across market-making, OTC, treasury, ventures, and fund-related business lines to improve conversion efficiency and long-term value creation.
Support institutional fundraising and LP relationship management, including investor outreach, investor communication, due diligence coordination, subscription processes, and capital onboarding.
Clearly communicate Klein Labs’ business model, fund strategy, return profile, risk framework, and differentiated strengths to external partners and investors, building trust and improving conversion.
Manage and continuously optimize external materials, including company introductions, business decks, fundraising decks, one-pagers, FAQs, DDQs, and investor update materials, ensuring professionalism and consistency in external messaging.
Represent Klein Labs in key business negotiations, industry events, important external meetings, and strategic partnership discussions.
Work cross-functionally with management, research, trading, legal, and operations teams to drive partnership execution, fundraising progress, and long-term relationship management.
Support the expansion and management of the global BD team as the business grows, including KPI setting and performance culture development.
Requirements
3+ years of experience in business development, strategic partnerships, institutional fundraising, investor relations, sales, or related functions, with prior crypto industry experience preferred.
A clear and verifiable track record in driving business growth, partnership conversion, or fundraising outcomes, with the ability to independently move initiatives forward.
Strong understanding of the Web3 ecosystem, crypto market structure, token economics, and strategic partnership dynamics.
Familiarity with how to engage and build trust with projects, exchanges, funds, family offices, HNWIs, institutional investors, and crypto-native LPs.
Strong communication, relationship-building, material preparation, and process management skills, with the ability to coordinate across multiple stakeholders in complex situations.
Highly execution-oriented, results-driven, and capable of building systems and processes in a fast-paced, high-ownership environment.
Professional working proficiency in English.
Candidates based in Singapore or Dubai are strongly preferred.
Existing relationships with institutions, family offices, HNWIs, crypto-native LPs, exchanges, or project teams are a strong plus. Experience in liquidity management, trading services, funds, asset management, primary markets, or related market structure is also preferred.
What We Offer
A key role with direct exposure to Klein Labs’ core business growth, strategic partnerships, and capital network development.
Close collaboration with the founding team and senior leadership, with direct involvement in shaping business direction, fundraising strategy, and external positioning.
Competitive compensation, performance-based incentives, and long-term upside.
Direct access to high-quality deal flow, institutional relationships, and primary market opportunities.
Deep involvement across CEX, DEX, and both on-chain and off-chain collaboration ecosystems.
A highly flexible, low-hierarchy, and deeply crypto-native working environment.
You will work closely with the founding team to develop and execute global BD and fundraising strategies, expand and maintain relationships with projects, exchanges, funds, family offices, high-net-worth individuals, and other key ecosystem participants, and continuously drive business partnerships, capital introduction, and long-term strategic value creation. This role is ideal for someone with strong execution, mature business judgment, and a solid understanding of capital markets, who can thrive in a fast-paced, high-autonomy, crypto-native environment.
Responsibilities
Develop and execute business development, strategic partnership, and fundraising plans across Klein Labs’ business lines, driving revenue growth, partnership conversion, and capital introduction.
Build and maintain long-term relationships with exchanges, projects, DAOs, market makers, funds, family offices, HNWIs, and other key ecosystem participants.
Design and implement partnership models across market-making, OTC, treasury, ventures, and fund-related business lines to improve conversion efficiency and long-term value creation.
Support institutional fundraising and LP relationship management, including investor outreach, investor communication, due diligence coordination, subscription processes, and capital onboarding.
Clearly communicate Klein Labs’ business model, fund strategy, return profile, risk framework, and differentiated strengths to external partners and investors, building trust and improving conversion.
Manage and continuously optimize external materials, including company introductions, business decks, fundraising decks, one-pagers, FAQs, DDQs, and investor update materials, ensuring professionalism and consistency in external messaging.
Represent Klein Labs in key business negotiations, industry events, important external meetings, and strategic partnership discussions.
Work cross-functionally with management, research, trading, legal, and operations teams to drive partnership execution, fundraising progress, and long-term relationship management.
Support the expansion and management of the global BD team as the business grows, including KPI setting and performance culture development.
Requirements
3+ years of experience in business development, strategic partnerships, institutional fundraising, investor relations, sales, or related functions, with prior crypto industry experience preferred.
A clear and verifiable track record in driving business growth, partnership conversion, or fundraising outcomes, with the ability to independently move initiatives forward.
Strong understanding of the Web3 ecosystem, crypto market structure, token economics, and strategic partnership dynamics.
Familiarity with how to engage and build trust with projects, exchanges, funds, family offices, HNWIs, institutional investors, and crypto-native LPs.
Strong communication, relationship-building, material preparation, and process management skills, with the ability to coordinate across multiple stakeholders in complex situations.
Highly execution-oriented, results-driven, and capable of building systems and processes in a fast-paced, high-ownership environment.
Professional working proficiency in English.
Candidates based in Singapore or Dubai are strongly preferred.
Existing relationships with institutions, family offices, HNWIs, crypto-native LPs, exchanges, or project teams are a strong plus. Experience in liquidity management, trading services, funds, asset management, primary markets, or related market structure is also preferred.
What We Offer
A key role with direct exposure to Klein Labs’ core business growth, strategic partnerships, and capital network development.
Close collaboration with the founding team and senior leadership, with direct involvement in shaping business direction, fundraising strategy, and external positioning.
Competitive compensation, performance-based incentives, and long-term upside.
Direct access to high-quality deal flow, institutional relationships, and primary market opportunities.
Deep involvement across CEX, DEX, and both on-chain and off-chain collaboration ecosystems.
A highly flexible, low-hierarchy, and deeply crypto-native working environment.
Payment in Crypto
Mykhailo Liashenko
Senior Blockchain Engineer for RWAHub
Florida City, USA
Florida City, USA
Full time
Remote
The Role
We are hiring a Senior Blockchain Developer to design and build smart contract systems across multiple client and internal projects.
You will work on a variety of blockchain applications - from DeFi protocols to tokenized systems and Web3 platforms - ensuring high standards in security, scalability, and architecture.
This is a senior-level, hands-on role with exposure to multiple products and industries.
What You’ll Do
Design, develop, and deploy smart contracts using Solidity
Implement token standards (ERC-20, ERC-721, ERC-1155) and custom logic
Build and maintain contract architectures across multiple projects
Ensure security, audit readiness, and upgradeability
Optimize gas usage and performance
Collaborate with backend and frontend teams for integrations
Participate in code reviews and technical decision-making
Contribute to documentation and internal best practices
What We’re Looking For
4+ years of experience in blockchain / smart contract development
Strong expertise in Solidity and EVM-based ecosystems
Experience with Ethereum and L2s (Polygon, Arbitrum, Optimism)
Solid understanding of smart contract security and vulnerabilities
Experience with Hardhat, Foundry, or similar frameworks
Strong software engineering fundamentals (testing, Git, CI/CD)
Ability to work across multiple projects and adapt quickly
Nice to Have
Experience with DeFi protocols, staking, or token economies
Experience working with auditors or security reviews
Familiarity with upgradeable contracts (proxy patterns)
Backend experience (Node.js / TypeScript)
Experience in client-facing or consulting environments
Tech Stack
Solidity · Ethereum · Polygon · Arbitrum
Hardhat / Foundry · Node.js · TypeScript
React · ethers.js · IPFS
Why Join
Work across a diverse portfolio of blockchain projects
Exposure to both client work and internal ventures
Opportunity to influence architecture and technical direction
Collaborative, globally distributed team
Fast-paced environment with continuous learning
What Success Looks Like
Secure, production-ready smart contracts delivered across projects
Successful audits with minimal critical issues
Scalable and reusable contract architectures
Strong collaboration with cross-functional teams
Consistent delivery across multiple initiatives
How to Apply
Please submit:
Resume or LinkedIn
GitHub profile (required)
Examples of smart contracts or blockchain project
Apply Directly:
https://rwahubassets.com/
Applications & Inquiries:
support@rwahubassets.com
Equal Opportunity
We value diversity and are committed to building an inclusive environment.
We are hiring a Senior Blockchain Developer to design and build smart contract systems across multiple client and internal projects.
You will work on a variety of blockchain applications - from DeFi protocols to tokenized systems and Web3 platforms - ensuring high standards in security, scalability, and architecture.
This is a senior-level, hands-on role with exposure to multiple products and industries.
What You’ll Do
Design, develop, and deploy smart contracts using Solidity
Implement token standards (ERC-20, ERC-721, ERC-1155) and custom logic
Build and maintain contract architectures across multiple projects
Ensure security, audit readiness, and upgradeability
Optimize gas usage and performance
Collaborate with backend and frontend teams for integrations
Participate in code reviews and technical decision-making
Contribute to documentation and internal best practices
What We’re Looking For
4+ years of experience in blockchain / smart contract development
Strong expertise in Solidity and EVM-based ecosystems
Experience with Ethereum and L2s (Polygon, Arbitrum, Optimism)
Solid understanding of smart contract security and vulnerabilities
Experience with Hardhat, Foundry, or similar frameworks
Strong software engineering fundamentals (testing, Git, CI/CD)
Ability to work across multiple projects and adapt quickly
Nice to Have
Experience with DeFi protocols, staking, or token economies
Experience working with auditors or security reviews
Familiarity with upgradeable contracts (proxy patterns)
Backend experience (Node.js / TypeScript)
Experience in client-facing or consulting environments
Tech Stack
Solidity · Ethereum · Polygon · Arbitrum
Hardhat / Foundry · Node.js · TypeScript
React · ethers.js · IPFS
Why Join
Work across a diverse portfolio of blockchain projects
Exposure to both client work and internal ventures
Opportunity to influence architecture and technical direction
Collaborative, globally distributed team
Fast-paced environment with continuous learning
What Success Looks Like
Secure, production-ready smart contracts delivered across projects
Successful audits with minimal critical issues
Scalable and reusable contract architectures
Strong collaboration with cross-functional teams
Consistent delivery across multiple initiatives
How to Apply
Please submit:
Resume or LinkedIn
GitHub profile (required)
Examples of smart contracts or blockchain project
Apply Directly:
https://rwahubassets.com/
Applications & Inquiries:
support@rwahubassets.com
Equal Opportunity
We value diversity and are committed to building an inclusive environment.
Payment in Crypto