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
Circle
Website
www.circle.comCompany size
Not specified
Location
United States
Description
Not specified
Status
Worklo
Senior Blockchain Developer based Next.js+Rust
California City, USA +2
California City, USA +2
Full time
Remote
We're looking for an experienced Senior Blockchain Developer with strong expertise in Next.js and Rust to join our growing team.
Requirements:
5+ years of software development experience
Strong experience with Next.js and Rust
Experience building blockchain/Web3 applications
Solid understanding of smart contracts, blockchain protocols, or cryptography
Excellent problem-solving and communication skills
Location: United States (preferred)
Salary: $80,000–$100,000/year (depending on experience)
If you're passionate about building scalable blockchain applications, we'd love to hear from you.
📩 If you're interested, please apply through LaborX with your profile, resume, GitHub, and any relevant project links.
Requirements:
5+ years of software development experience
Strong experience with Next.js and Rust
Experience building blockchain/Web3 applications
Solid understanding of smart contracts, blockchain protocols, or cryptography
Excellent problem-solving and communication skills
Location: United States (preferred)
Salary: $80,000–$100,000/year (depending on experience)
If you're passionate about building scalable blockchain applications, we'd love to hear from you.
📩 If you're interested, please apply through LaborX with your profile, resume, GitHub, and any relevant project links.
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
Worklo
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
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
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