Senior Software Engineer - Special Projects
Status
Seattle, USA
Full time
Remote
Compensation is not specified
Role
Software Engineer
Description
Circle is a pioneering financial technology company actively immersed in the advancement of the internet of money. Our focus lies in revolutionizing how value travels globally, almost instantaneously, and at reduced costs compared to traditional settlement systems. This revolutionary internet layer is shaping new payment possibilities, enhancing commerce, and influencing markets to foster global economic growth and bolster inclusivity. Our infrastructure, notably USDC, a blockchain-based dollar, empowers businesses, institutions, and developers to embrace these advancements and seize opportunities stemming from this pivotal fusion of money and technology.
About the Position:
Join our dynamic team at Circle as a proficient Senior/Staff Software Engineer dedicated to our USDC Smart Contract team. In this role, you will tactically lead the development and expansion of smart contracts for USDC across diverse blockchain protocols such as Ethereum, Solana, Cosmos, and more.
Key Responsibilities:
- Design, develop, test, and deploy secure smart contracts to ensure smooth and protected transactions.
- Upgrade existing smart contracts for increased efficiency, safety, and developer productivity.
- Incorporate top-tier security practices and optimize performance.
- Conduct risk evaluations concerning smart contract development on various blockchain platforms to identify vulnerabilities and implement appropriate protective measures for enhanced security and robustness.
Desired Skills and Experience:
Senior Software Engineer (III):
- Over 4 years of professional software development experience, inclusive of internships.
- More than 2 years of validated smart contract development experience on blockchain platforms.
- Strong proficiency in programming languages used for non-EVM smart contracts like Rust, Go, and others.
- Demonstrated expertise in at least one leading non-EVM blockchain ecosystem such as Cosmos or Solana.
- Proven track record in designing, coding, testing, and deploying secure and efficient smart contracts.
- Robust focus on implementing security best practices and integrating security measures in smart contract development.
Staff Software Engineer (IV) Requirements:
All criteria for a Senior Software Engineer with the following additions:
- Over 7 years of professional software development experience, encompassing internships.
- More than 4 years of established smart contract development expertise on blockchain platforms.
- Exceptional knowledge of non-EVM programming languages and technology stacks.
- Deep comprehension of blockchain principles and various blockchain and web3 protocols.
- Ability to lead technical teams, provide mentorship to junior engineers, and collaborate effectively with cross-functional teams.
- Effective communication skills to foster consensus-building within team members and stakeholders.
Additional Information:
- The position welcomes day-one PERM sponsorship for eligible candidates.
- Compensation is determined by factors like relevant experience, skill set, qualifications, and organizational requirements.
Com pensation Summaries:
- Starting salaries for Senior Software Engineers range from $147,500 - $195,000 with an annual bonus target of 12.5%.
- For Staff Software Engineers, base salaries range between $172,500 - $227,500 coupled with an annual bonus target of 15%.
Benefits and Discretionary Policy: Employees enjoy equity and benefits, including medical, dental, vision, and 401(k). Our discretionary vacation policy along with paid sick leave and holidays contribute to your work-life balance.
Diversity & Equality:
Circle values diversity and offers an equal opportunity workplace, fostering a culture where differences are embraced. We are committed to inclusivity and do not discriminate on the basis of various factors.
Stay innovative, challenge the status quo and redefine the future in financial technology with our empowered team at Circle!
Skills Required
Circle
Website
www.circle.comCompany size
Not specified
Location
United States
Description
Not specified
Status
Ment Tech
Senior Software Engineer (Blockchain)
Mumbai, India +3
Mumbai, India +3
Full time
Remote
About MentTech
MentTech is a forward-thinking technology company dedicated to transforming how mentoring and learning are delivered in the digital age. By combining advanced tools, intelligent systems, and a human-first approach, MentTech helps individuals, teams, and organizations harness the power of mentorship to unlock potential, build skills, and achieve lasting growth.
The Role
We are seeking a Smart Contract Developer responsible for ensuring that game listings within MentTech work properly and ensuring compliance with all game store policies.
Key Responsibilities:
• Architect, implement, and deploy secure smart contracts for an on-chain Play-to-Earn GameFi ecosystem
• Lead contract design decisions with a focus on robustness, auditability, gas efficiency, and resilience to attack vectors
• Mentor/junior developers: perform code reviews, establish standards, best practices in security & testing
• Collaborate cross-functionally with game designers, backend, QA, and security teams to align smart contract features with product roadmap
Qualifications:
• 2+ years hands‐on experience developing & deploying smart contracts (Solidity / EVM or equivalent) in production environments
• Track record of writing secure contracts, familiarity with common vulnerabilities (reentrancy, integer over/underflow, front-running, flash loans, etc.)
• Experience with audits, formal verification, fuzz testing, or other advanced contract assurance methods
• Strong test suite / CI workflow skills; comfortable using tools like Hardhat, Foundry, Truffle etc.
• Solid understanding of GameFi mechanics and how on-chain economics work
Bonus Points:
• Experience on multiple EVM chains or Layer-2 / sidechains
• Knowledge of cross-chain bridges, oracles, NFTs, tokenomics design
• Contributions to open-source security tooling or prior audit reports or published code you’re proud of
Why join MentTech?
At MentTech, we cultivate a culture of flexibility, autonomy, and the freedom to make a real impact on the broader Web3 ecosystem. Experience the advantages of a fully remote working environment where your expertise and contributions are rewarded with competitive compensation tailored to your role and project influence.
Ment Tech Labs
• Employee Equity & Incentives: Unlock future growth with equity and other potential incentives.
• Entrepreneurial Culture: Join a collaborative environment where we innovate together as partners.
• Cutting-edge Innovation: Work at the forefront of gaming and blockchain.
• Key Strategic Projects: Be part of transformative initiatives that are redefining the gaming landscape.
• Remote Flexibility: Enjoy a truly flexible, fully remote work setup that supports your lifestyle.
• Talented Team: Collaborate with a team of passionate, driven, and skilled professionals.
• Community Impact: Contribute to the growth and success of the Web3 and gaming communities.
• Flexible Payment Options: Receive payments in crypto or fiat, tailored to your preference.
• Growth Opportunities: Access valuable learning experiences and development paths.
MentTech Labs, Inc. is an equal opportunities workplace that doesn’t discriminate based on race, ethnicity, gender, ancestry, national origin, religion, sex, sexual orientation, gender identity, age disability, veteran status, genetic information, marital status, or any other legally protected status.
MentTech is a forward-thinking technology company dedicated to transforming how mentoring and learning are delivered in the digital age. By combining advanced tools, intelligent systems, and a human-first approach, MentTech helps individuals, teams, and organizations harness the power of mentorship to unlock potential, build skills, and achieve lasting growth.
The Role
We are seeking a Smart Contract Developer responsible for ensuring that game listings within MentTech work properly and ensuring compliance with all game store policies.
Key Responsibilities:
• Architect, implement, and deploy secure smart contracts for an on-chain Play-to-Earn GameFi ecosystem
• Lead contract design decisions with a focus on robustness, auditability, gas efficiency, and resilience to attack vectors
• Mentor/junior developers: perform code reviews, establish standards, best practices in security & testing
• Collaborate cross-functionally with game designers, backend, QA, and security teams to align smart contract features with product roadmap
Qualifications:
• 2+ years hands‐on experience developing & deploying smart contracts (Solidity / EVM or equivalent) in production environments
• Track record of writing secure contracts, familiarity with common vulnerabilities (reentrancy, integer over/underflow, front-running, flash loans, etc.)
• Experience with audits, formal verification, fuzz testing, or other advanced contract assurance methods
• Strong test suite / CI workflow skills; comfortable using tools like Hardhat, Foundry, Truffle etc.
• Solid understanding of GameFi mechanics and how on-chain economics work
Bonus Points:
• Experience on multiple EVM chains or Layer-2 / sidechains
• Knowledge of cross-chain bridges, oracles, NFTs, tokenomics design
• Contributions to open-source security tooling or prior audit reports or published code you’re proud of
Why join MentTech?
At MentTech, we cultivate a culture of flexibility, autonomy, and the freedom to make a real impact on the broader Web3 ecosystem. Experience the advantages of a fully remote working environment where your expertise and contributions are rewarded with competitive compensation tailored to your role and project influence.
Ment Tech Labs
• Employee Equity & Incentives: Unlock future growth with equity and other potential incentives.
• Entrepreneurial Culture: Join a collaborative environment where we innovate together as partners.
• Cutting-edge Innovation: Work at the forefront of gaming and blockchain.
• Key Strategic Projects: Be part of transformative initiatives that are redefining the gaming landscape.
• Remote Flexibility: Enjoy a truly flexible, fully remote work setup that supports your lifestyle.
• Talented Team: Collaborate with a team of passionate, driven, and skilled professionals.
• Community Impact: Contribute to the growth and success of the Web3 and gaming communities.
• Flexible Payment Options: Receive payments in crypto or fiat, tailored to your preference.
• Growth Opportunities: Access valuable learning experiences and development paths.
MentTech Labs, Inc. is an equal opportunities workplace that doesn’t discriminate based on race, ethnicity, gender, ancestry, national origin, religion, sex, sexual orientation, gender identity, age disability, veteran status, genetic information, marital status, or any other legally protected status.
Payment in Crypto
HubsAI
Senior web3 engineer
Treynor, USA
Treynor, USA
Part time
Remote
About the Project:
We’re building a SocialFi platform combining real estate and DeFi. After launching our MVP, we’re now progressing to version 2.
Role:
Join our remote team to develop website, smart contracts, integrate blockchain features, and ensure platform security.
Responsibilities:
- Develop and deploy smart contracts on Ethereum or Layer 2.
- Integrate wallet connect and decentralized features.
- Collaborate and direct contribute with frontend/backend teams.
- Conduct security audits.
Requirements:
- Experience with React, Ethers.js, Web3.js.
- Familiarity with wallet extensions and DeFi protocols.
- Ability to fix errors within 1 hour during tests.
- Comfortable working independently in a remote setup.
Nice to Have:
- Knowledge of cross-chain protocols or cryptography.
- Experience in social finance or real estate blockchain projects.
Application:
Send your resume and Linkedin profile. Selected candidates will do a quick coding test.
Contact: contact@hubsai.net
Join us to help shape the future of SocialFi!
We’re building a SocialFi platform combining real estate and DeFi. After launching our MVP, we’re now progressing to version 2.
Role:
Join our remote team to develop website, smart contracts, integrate blockchain features, and ensure platform security.
Responsibilities:
- Develop and deploy smart contracts on Ethereum or Layer 2.
- Integrate wallet connect and decentralized features.
- Collaborate and direct contribute with frontend/backend teams.
- Conduct security audits.
Requirements:
- Experience with React, Ethers.js, Web3.js.
- Familiarity with wallet extensions and DeFi protocols.
- Ability to fix errors within 1 hour during tests.
- Comfortable working independently in a remote setup.
Nice to Have:
- Knowledge of cross-chain protocols or cryptography.
- Experience in social finance or real estate blockchain projects.
Application:
Send your resume and Linkedin profile. Selected candidates will do a quick coding test.
Contact: contact@hubsai.net
Join us to help shape the future of SocialFi!
Payment in Crypto
Michael Har
Junior / Middle Metaverse Developer (Unity / Web3 / VR)
Manzhouli, China
Manzhouli, China
Full time
Remote
We are looking for a Metaverse Developer to help build interactive virtual environments and immersive digital experiences. The role involves developing 3D worlds, integrating Web3 technologies, and working with modern tools for real-time applications.
You will work with Unity, WebGL, and blockchain technologies to create engaging metaverse features and optimize them for performance across different devices. The developer will collaborate with designers and backend engineers to deliver scalable and stable products.
Requirements include experience with Unity and C#, understanding of 3D development, Web3 or blockchain basics, and familiarity with Git and API integration. Experience with VR/AR, NFTs, or multiplayer systems is a plus.
We offer remote work, flexible hours, crypto payments, and the opportunity to build innovative metaverse products.
You will work with Unity, WebGL, and blockchain technologies to create engaging metaverse features and optimize them for performance across different devices. The developer will collaborate with designers and backend engineers to deliver scalable and stable products.
Requirements include experience with Unity and C#, understanding of 3D development, Web3 or blockchain basics, and familiarity with Git and API integration. Experience with VR/AR, NFTs, or multiplayer systems is a plus.
We offer remote work, flexible hours, crypto payments, and the opportunity to build innovative metaverse products.
Payment in Crypto
Neonflick
Web3 Fullstack Developer
Part time
Remote
🌐 About Us
Neonflick is a tech organization specializing in Web3 development.
We believe Web3 solutions are not as popular as they could be — mainly due to complexity. Our mission is to simplify the user experience and make decentralized technology more accessible and easy to use for everyone.
🚀 About the Role
We are looking for a Web3 Fullstack Developer who is passionate about decentralized technologies and excited to contribute to building meaningful Web3 products. You will work on developing new products, improving existing ones, and fixing bugs, all while proposing innovative ideas to enhance our platform.
🔹 Responsibilities
Develop functional and user-friendly Web3 products
Improve and optimize existing products and features
Identify and fix bugs or issues in the system
Propose and implement new ideas for product development
Collaborate with the team to ensure high-quality software delivery
🔹 Requirements
Strong interest in Web3 / blockchain / decentralized technologies
Fullstack development experience (frontend + backend)
Experience with smart contracts and decentralized frameworks is a plus
Problem-solving skills and attention to detail
Ability to work independently and proactively
🔹 What You Get
Early-stage involvement in a Web3 tech organization
Influence over product development and feature design
Opportunity to build experience and a portfolio in the Web3 space
Potential long-term collaboration and future compensation as the project grows
A chance to contribute to making Web3 simpler and more accessible
⚠️ Important
This is an unpaid position. We are looking for someone motivated by vision, learning, and long-term impact rather than immediate salary.
If you are passionate about Web3 and building meaningful decentralized products, we’d love to hear from you.
Neonflick is a tech organization specializing in Web3 development.
We believe Web3 solutions are not as popular as they could be — mainly due to complexity. Our mission is to simplify the user experience and make decentralized technology more accessible and easy to use for everyone.
🚀 About the Role
We are looking for a Web3 Fullstack Developer who is passionate about decentralized technologies and excited to contribute to building meaningful Web3 products. You will work on developing new products, improving existing ones, and fixing bugs, all while proposing innovative ideas to enhance our platform.
🔹 Responsibilities
Develop functional and user-friendly Web3 products
Improve and optimize existing products and features
Identify and fix bugs or issues in the system
Propose and implement new ideas for product development
Collaborate with the team to ensure high-quality software delivery
🔹 Requirements
Strong interest in Web3 / blockchain / decentralized technologies
Fullstack development experience (frontend + backend)
Experience with smart contracts and decentralized frameworks is a plus
Problem-solving skills and attention to detail
Ability to work independently and proactively
🔹 What You Get
Early-stage involvement in a Web3 tech organization
Influence over product development and feature design
Opportunity to build experience and a portfolio in the Web3 space
Potential long-term collaboration and future compensation as the project grows
A chance to contribute to making Web3 simpler and more accessible
⚠️ Important
This is an unpaid position. We are looking for someone motivated by vision, learning, and long-term impact rather than immediate salary.
If you are passionate about Web3 and building meaningful decentralized products, we’d love to hear from you.
Amir F
Full Stack Developer – Kick-to-Earn Gaming Platform
Istanbul, Türkiye
Istanbul, Türkiye
Full time
Remote
About the Project
We're building a mobile-first competitive gaming platform where players step onto the virtual field and earn rewards through penalty kick matches. The platform includes real-time gameplay, tournaments, leaderboards, an in-app store, token management (deposit/withdraw), daily quests, and a player progression system. Think casual gaming meets Web3 — fast, competitive, and rewarding.Current StateThe frontend is actively under development with a strong foundation already in place:
~30+ reusable UI components (modals, tabs, cards, buttons, inputs, badges, etc.)
Multiple feature modules: penalty game, tournaments, leaderboard, user profiles, store, token management
Figma-driven design system with a polished dark-themed UI
Animated goalkeeper characters using Lottie/dotLottie with SVG body parts
SPA routing and responsive mobile-first layouts
Tech Stack
Frontend: Next.js 16, React 19, TypeScript, Tailwind CSS 4
Animations: Lottie / dotLottie
Design Pipeline: Figma with MCP integration for design-to-code workflow
Tooling: ESLint, PostCSS, Turbopack
What You'll Do
Build and maintain frontend features with pixel-accurate implementation from Figma designs
Architect and develop backend services (APIs, authentication, game logic, matchmaking, token transactions)
Integrate blockchain/token functionality for the earn-and-spend economy
Design and manage the database layer (user data, match results, tournament state, transaction history)
Set up real-time infrastructure for live matches and leaderboard updates
Write clean, scalable TypeScript across the full stack
Collaborate closely with design to maintain high visual fidelity
Requirements
3+ years of production experience with React and Next.js
Strong TypeScript skills
Solid backend experience (Node.js, Express/Fastify/Hono, or similar)
Database design and management (PostgreSQL, MongoDB, or equivalent)
Experience building and consuming REST or GraphQL APIs
Understanding of real-time systems (WebSockets, SSE, or similar)
Proficiency with Tailwind CSS and responsive, mobile-first design
Comfort working from Figma designs with attention to detail
Nice to Have
Experience with Web3 / blockchain integrations (wallet connection, token transactions)
Familiarity with Lottie animations and interactive game-like UIs
Experience with matchmaking or game server architecture
Knowledge of payment/transaction systems
Experience with CI/CD pipelines and deployment (Vercel, Docker, etc.)
If you enjoy building products at the intersection of gaming and crypto, and you care about clean architecture and polished UI, we'd love to hear from you.Feel free to adjust the engagement type, compensation details, timezone preferences, and any company-specific info before posting.
We're building a mobile-first competitive gaming platform where players step onto the virtual field and earn rewards through penalty kick matches. The platform includes real-time gameplay, tournaments, leaderboards, an in-app store, token management (deposit/withdraw), daily quests, and a player progression system. Think casual gaming meets Web3 — fast, competitive, and rewarding.Current StateThe frontend is actively under development with a strong foundation already in place:
~30+ reusable UI components (modals, tabs, cards, buttons, inputs, badges, etc.)
Multiple feature modules: penalty game, tournaments, leaderboard, user profiles, store, token management
Figma-driven design system with a polished dark-themed UI
Animated goalkeeper characters using Lottie/dotLottie with SVG body parts
SPA routing and responsive mobile-first layouts
Tech Stack
Frontend: Next.js 16, React 19, TypeScript, Tailwind CSS 4
Animations: Lottie / dotLottie
Design Pipeline: Figma with MCP integration for design-to-code workflow
Tooling: ESLint, PostCSS, Turbopack
What You'll Do
Build and maintain frontend features with pixel-accurate implementation from Figma designs
Architect and develop backend services (APIs, authentication, game logic, matchmaking, token transactions)
Integrate blockchain/token functionality for the earn-and-spend economy
Design and manage the database layer (user data, match results, tournament state, transaction history)
Set up real-time infrastructure for live matches and leaderboard updates
Write clean, scalable TypeScript across the full stack
Collaborate closely with design to maintain high visual fidelity
Requirements
3+ years of production experience with React and Next.js
Strong TypeScript skills
Solid backend experience (Node.js, Express/Fastify/Hono, or similar)
Database design and management (PostgreSQL, MongoDB, or equivalent)
Experience building and consuming REST or GraphQL APIs
Understanding of real-time systems (WebSockets, SSE, or similar)
Proficiency with Tailwind CSS and responsive, mobile-first design
Comfort working from Figma designs with attention to detail
Nice to Have
Experience with Web3 / blockchain integrations (wallet connection, token transactions)
Familiarity with Lottie animations and interactive game-like UIs
Experience with matchmaking or game server architecture
Knowledge of payment/transaction systems
Experience with CI/CD pipelines and deployment (Vercel, Docker, etc.)
If you enjoy building products at the intersection of gaming and crypto, and you care about clean architecture and polished UI, we'd love to hear from you.Feel free to adjust the engagement type, compensation details, timezone preferences, and any company-specific info before posting.
Payment in Crypto