Senior Software Engineer, Backend

Status
Full time
Remote
Compensation is not specified
Role
Software Engineer
Description

Circle is a fintech company that operates in the realm of digital currency and blockchain technology. We are at the forefront of the emerging internet of money, enabling value to be exchanged digitally on a global scale, swiftly and cost-effectively. Our innovative infrastructure, including the blockchain-based dollar called USDC, empowers businesses, institutions, and developers to leverage the possibilities presented by this digital ecosystem.

What We Offer:

At Circle, we prioritize transparency and stability in our operations. As we expand our presence across various jurisdictions, we aim for agility and effectiveness in everything we do. Our employees embody our core company values of being Multistakeholder, Mindful, Driven by Excellence, and High Integrity. In a remote work environment, we thrive on collaboration, with each individual making a meaningful contribution to our collective success. Our work culture encourages fresh ideas and ensures that everyone has a stake in our organization.

Role Overview:

We are currently seeking a highly skilled and experienced Senior Backend Engineer to join our dynamic team at Circle. As a Senior Backend Engineer, you will play a key role in designing and developing various services on our wallet infrastructure while maintaining the underlying code.

Your Responsibilities:

In this role, your main tasks will include:

  • Analyzing data, processes, and codes to identify areas for improvement and develop effective solutions
  • Creating services, APIs, and SDKs that align with data protection standards and facilitate the implementation of protection controls for other developers
  • Collaborating with front-end developers and other team members to establish objectives and enhance the functionality and coherence of the codebase
  • Involvement in the entire application lifecycle
  • Building reusable code of high quality for future use
  • Conducting whitebox tests and optimizing performance
  • Actively participating in conferences and educational programs
  • Keeping up to date with new and emerging technologies and providing training and support to team members
  • Taking on project leadership as required

Our Core Values:

In everything you do at Circle, you will embody our four core values:

  • Multistakeholder: Demonstrating dedication and commitment to our customers, shareholders, employees, families, and local communities
  • Mindful: Displaying respect, active listening, and attention to detail
  • Driven by Excellence: Relentlessly pursuing excellence, rejecting mediocrity, and working intensively to achieve goals and ensure customer success
  • High Integrity: Valuing open and honest communication, holding yourself to high moral and ethical standards, and rejecting manipulation, dishonesty, and intolerance

Qualifications:

To thrive in this role, you should possess the following qualifications and skills:

  • Minimum of 4 years of professional software development experience, working with object-oriented languages such as Java and Go
  • Bachelor's degree or equivalent experience in Computer Science or a closely related field
  • Familiarity with Golang Web Frameworks like Gin and Fasthttp, and knowledge of Golang development tools like go mod and go lint
  • Experience with database operations, including MySQL, PostgreSQL, and NoSQL, and proficiency in operating databases through raw commands
  • Knowledge and experience in unit test development, with a focus on producing high-quality code
  • Strong understanding of microservices development cycle, programming techniques, and tools
  • Familiarity with cryptography is a plus
  • Excellent project and time management skills
  • Strong communication skills, with the ability to collaborate effectively with remote teams, share ideas, and present concepts
  • Self-starter mentality, thriving in a fast-paced environment and able to independently ship software that improves user experience while constantly improving your own work
  • Past experience leading technically on architecture and system design for teams of 2-4 members

Circle is proud to be an equal opportunity employer that values diversity. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. In certain locations, Circle participates in the E-Verify Program as required by law.

Skills Required
Avatar
Circle
Company size
Not specified
Location
United States
Description
Not specified
Status

More Full-time Jobs

Show more

Full Stack Engineer focusing on Blockchain Technologies

Full time
Remote
Worklo is building the future of professional services automation by combining our core PSA platform with a blockchain-powered salary distribution system. The platform automates compensation based on project data, time entries, role assignments, milestones, and secure on-chain payroll execution.
We are looking for a highly capable Full Stack / Blockchain Engineer who can own both SaaS product development and blockchain infrastructure. This is a high-ownership role where you will help shape Worklo PSA and our blockchain payroll architecture from the ground up.
Key Responsibilities
* Build full-stack product features using Next.js, TypeScript, Node.js/Express, Supabase, PostgreSQL, React, shadcn/ui, and Tailwind CSS
* Design secure APIs, database schemas, authentication flows, and Supabase RLS policies
* Develop Solidity smart contracts for salary calculation and automated payroll distribution
* Build blockchain integrations for wallet registry, MetaMask/WalletConnect, payroll execution, and event syncing
* Deploy and manage smart contracts on Polygon or other EVM-compatible networks
* Implement dashboards for payroll visibility, wallet management, and transaction history
* Write tests for smart contracts using Hardhat, Foundry, or similar tools
* Improve performance, security, observability, and overall system architecture
Requirements
* 5+ years of full-stack software development experience
* 5+ years of blockchain development experience with deployed smart contracts
* Strong skills in TypeScript, Node.js, React, Next.js, PostgreSQL, and REST APIs
* Strong Solidity knowledge, including access control, reentrancy protection, gas optimization, and upgradeability
* Experience with ethers.js, viem, ERC-20 tokens, stablecoins, and EVM-compatible networks
* Ability to work independently in a remote-first, async startup environment
Nice to Have
* Experience with Supabase, Next.js App Router, React Server Components, Foundry, Hardhat, OpenZeppelin, The Graph, DeFi systems, multi-sig wallets, or multi-tenant SaaS platforms
Payment in Crypto
7,000
Monthly
See details

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.
Payment in Crypto
11,667-18,333
Monthly
See details

Senior blockchain and frontend developer

Part time
Remote
Currently, our team is working on crypto betting website development that is for old customer who lives in Luxembourg.
There are 7 developers in our team right now.
We just started Front-UI development but our current progress is getting slowly so we are looking for developers who has experience in Blockchain development.
For this project, you need to have proven experience in React, TypeScript, Node.js and Web3.js for Front-end Development or Solidity for Smart Contracts Development.
If you are interested, then we can discuss more details.
Thanks Regards. 
Payment in Crypto
41.67
Monthly
See details

Senior Blockchain Engineer

Full time
Remote
One More Game is looking for a Senior Blockchain Engineer to help build secure and scalable blockchain systems for our web3 gaming products. This role is focused on smart contract development, blockchain integration, and technical problem-solving in a remote, fast-moving environment. You will work closely with our engineering and product teams to design, build, test, and maintain blockchain features that support real users and game economies. ResponsibilitiesDesign, develop, test, and deploy smart contracts.Build secure and efficient blockchain integrations for web3 applications.Work with product and engineering teams to implement on-chain features.Review contract logic for performance, reliability, and security.Write clear technical documentation and testing coverage.Support debugging, maintenance, and upgrades for deployed contracts. Requirements3+ years of professional software engineering experience.Strong experience with Solidity and EVM-compatible blockchains.Hands-on experience with smart contract testing and deployment tools such as Foundry or Hardhat.Good understanding of blockchain architecture, wallets, transactions, and contract interactions.Experience building production blockchain applications.Strong communication skills and ability to work remotely. Preferred QualificationsExperience with GameFi, NFTs, DeFi, or Layer 2 solutions.Familiarity with backend or frontend integration for blockchain apps.Experience working in a remote startup environment. What to SubmitPlease include:GitHub profile.LinkedIn profile.A brief summary of your most relevant blockchain project.A short explanation of your role and technical contribution. About One More GameOne More Game is a US-based, fully remote company building blockchain-powered gaming infrastructure and digital experiences.
Payment in Crypto
10,000-15,000
Monthly
See details

Web3 & Smart contract developer

Silverstone, UK
Silverstone, UK
Part time
Remote
The project is being developed around a Web3 trading infrastructure platform. As part of our long-term vision, the UK team at Iress is building a scalable, secure, and production-ready platform for trading, staking, and DeFi functionality. To support this effort, we are looking for experienced blockchain developers who can contribute to smart contract development, architecture, security, and overall platform implementation. We are currently in the team-building phase and identifying developers whose experience aligns with the technical requirements of the project. Selected candidates will be invited to discuss the project roadmap, responsibilities, and collaboration model with the UK technical leadership team.
Payment in Crypto
500-667
Monthly
See details