IT - Defi Connectivity Developer - London
London, UK
Full time
Office
Compensation is not specified
Role
Software Engineer
Description
About us:
We are a leading player in the digital asset arena, dedicated to shaping the future ecosystem. Through consistent liquidity provision in varying market conditions, we have democratized institutional access to cryptocurrencies. Our reputation is anchored in cutting-edge technology and continuous product advancement, positioning us as the preferred partner for a wide range of international institutions. Established in 2015 and acquired by SBI, a prominent Japanese financial group, in 2020, we operate as an independent entity. Headquartered in the UK, with a global presence including offices in the US and Japan, we are regulated by the UK's Financial Conduct Authority.
We take pride in fostering a vibrant company culture and attracting individuals who not only bring top-tier skills but also align with our organizational values. If you are seeking a fulfilling role in a dynamic industry, read on.
About the role:
Joining our DeFi team as a Blockchain Developer involves creating and implementing strategies for liquidity provision, yield optimization, and automated trading within various DeFi protocols. Your responsibilities will revolve around developing robust systems that interface with multiple blockchain networks, ensuring security, efficiency, and profitability.
Key Responsibilities:
- Develop and manage software interfacing with blockchain networks.
- Deploy trading strategies across DeFi platforms.
- Design tools for wallet management, transaction tracking, and risk evaluation.
- Enhance code efficiency and reliability, with a focus on transaction fee optimization.
- Collaborate closely with trading and research teams to implement new strategies.
- Keep abreast of DeFi ecosystem advancements to identify potential opportunities.
- Participate in code reviews and uphold security best practices.
Required Skills and Experience:
- Demonstrated ownership mindset toward products.
- Exceptional communication and interpersonal abilities.
- Strong problem-solving skills and attention to detail.
- Self-driven with the capacity to take ownership of tasks and see them through to completion.
- At least 5 years of professional software development experience.
- Profound understanding of blockchain architecture and consensus mechanisms.
- Proficiency in working with blockchain networks through RPC nodes.
- Hands-on experience with cryptocurrency wallets and key management.
- Familiarity with key DeFi protocols such as Uniswap, Aave, and Compound.
- Proficiency in Python and/or Java.
- Knowledge of secure coding practices and cryptographic principles.
- Excellent analytical and problem-solving capabilities.
- Ability to thrive in an independent, fast-paced work environment.
Preferred Qualifications:
- Experience with EVM (Ethereum Virtual Machine) and Solidity.
- Familiarity with Solana Virtual Machine and Rust programming.
- Previous exposure to cryptocurrency trading, market making, or financial services.
- Hands-on experience with algorithmic trading systems.
- Contributions to open-source blockchain or DeFi projects.
- Understanding of market microstructure and trading principles.
We are a values-driven organization, epitomizing a strong cultural ethos that underpins our success. Our core values include ambitions to achieve remarkable feats and innovate continually, in-depth meritocracy, teamwork culture, and prudent risk management.
Equal Employment Opportunities Policy:
We champion equal employment opportunities for all, irrespective of background, and welcome applicants from diverse walks of life. Our policies maintain equality in all aspects of the employee lifecycle, based on merit and without discrimination related to race, color, religion, gender, age, disability, genetic information, marital status, or any other federally protected status. Discrimination in any form is not tolerated in our organization. We focus on creating an inclusive environment to attract, engage, retain, and empower the best talent available. Flexible working arrangements can be considered for all positions to support inclusivity.
Skills Required
B2C2
Website
www.b2c2.comCompany size
Not specified
Location
United States
Description
Not specified
Artem Fedotov
Senior Smart Contract Engineer
Miami, United States
Miami, United States
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
Hiring Process
Application review
Technical Assessment
Technical interview (Solidity & architecture)
Final discussion
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
Hiring Process
Application review
Technical Assessment
Technical interview (Solidity & architecture)
Final discussion
Payment in Crypto
SADR B
Web3 Sales & Business Development Partner📉
Remote, USA
Remote, USA
Full time
Remote
Oferli Partnership Announcement
Building the Future of Web3: Join Oferli as a Long-Term Core Partner
Oferli is officially expanding its core leadership. Having successfully established our foundational technical team, we are now opening strategic partnership opportunities for high-level Sales and Business Development Partners specialized in technology and Web3.
We are not looking for short-term contractors; we are searching for dedicated builders ready to scale and elevate this vision to a high international level from the ground up. Our tech team is already set, and now we are expanding to build out the sales and partnership side to bring in major projects.
For security, privacy, and professional efficiency, we have already prepared our dedicated workspace on Notion, along with a secure email-based group discussion space.
What We Are Looking For:
Proven expertise and network within the Technology and Web3 industries.
A long-term entrepreneurial mindset, fully committed to building a powerful ecosystem with us from day one.
Strong capabilities in driving strategic growth, securing high-value projects, and expanding our vision internationally.
If you are a serious professional ready to build this vision with us from the ground up, let’s connect!
Building the Future of Web3: Join Oferli as a Long-Term Core Partner
Oferli is officially expanding its core leadership. Having successfully established our foundational technical team, we are now opening strategic partnership opportunities for high-level Sales and Business Development Partners specialized in technology and Web3.
We are not looking for short-term contractors; we are searching for dedicated builders ready to scale and elevate this vision to a high international level from the ground up. Our tech team is already set, and now we are expanding to build out the sales and partnership side to bring in major projects.
For security, privacy, and professional efficiency, we have already prepared our dedicated workspace on Notion, along with a secure email-based group discussion space.
What We Are Looking For:
Proven expertise and network within the Technology and Web3 industries.
A long-term entrepreneurial mindset, fully committed to building a powerful ecosystem with us from day one.
Strong capabilities in driving strategic growth, securing high-value projects, and expanding our vision internationally.
If you are a serious professional ready to build this vision with us from the ground up, let’s connect!
Payment in Crypto
Yūta Watanabe
Data Analyst
Full time
Remote
ResponsibilitiesCollect, clean, analyze, and visualize both on-chain and off-chain data.Monitor and analyze key blockchain ecosystem metrics, including but not limited to:Active WalletsTransaction VolumeTotal Value Locked (TVL)User RetentionToken Distribution and CirculationLiquidity ChangesIdentify user behavior patterns through data analysis and provide insights to support product growth, operational strategies, and business decisions.Build and maintain dashboards and deliver regular analytical reports.Analyze trends across DeFi, NFT, GameFi, Layer 2, RWA, and other emerging Web3 sectors.Track competitor protocols and industry developments, producing market research and on-chain intelligence reports.Collaborate with Product, Marketing, Operations, and Engineering teams to drive data-driven decision making.Develop data models, KPI frameworks, and optimize analytics processes.RequirementsBasic QualificationsBachelor's degree or higher in Statistics, Mathematics, Computer Science, Financial Engineering, Economics, or a related field.2+ years of experience in data analytics.Experience in Web3, blockchain, cryptocurrency, or fintech industries is highly preferred.Strong interest in blockchain technology and familiarity with major blockchain ecosystems.Technical SkillsData AnalyticsStrong proficiency in SQL, including complex queries and advanced analytical techniques.Proficiency in Python and common data analysis libraries:PandasNumPyMatplotlibPlotlyFamiliarity with ETL processes and data warehouse architecture.Experience with:A/B TestingFunnel AnalysisUser Lifecycle AnalysisRetention AnalysisWeb3 Data AnalyticsStrong understanding of blockchain fundamentals:WalletsTransactionsSmart ContractsGas FeesEvent LogsToken Standards (ERC-20, ERC-721, ERC-1155)Additional requirements:Familiarity with EVM-based ecosystems:EthereumBNB ChainArbitrumBaseKnowledge of Solana and other non-EVM ecosystems is a plus.Ability to analyze on-chain fund flows, user behavior, and protocol-level data.Analytics ToolsHands-on experience with one or more of the following:Dune AnalyticsFlipside CryptoNansenGlassnodeToken TerminalArkhamBigQueryThe Graph (GraphQL)Data VisualizationExperience with:TableauPower BILooker StudioMetabaseAbility to transform complex datasets into actionable business insights and clear visualizations.Preferred QualificationsExperience analyzing DeFi, DEX, Lending, Staking, or Restaking protocols.Strong understanding of Tokenomics and token economy design.Experience with On-Chain Forensics and fund tracking.Familiarity with:MEV (Maximal Extractable Value)Liquidity mechanismsCross-chain bridgesExperience with machine learning, predictive analytics, or statistical modeling.Proven experience building and maintaining Dune Dashboards.Published blockchain research reports or on-chain analysis.Strong written and reading skills in English, with the ability to work directly with technical documentation.What We're Looking ForStrong analytical mindset and attention to detail.Excellent logical reasoning and problem-solving skills.Passion for crypto markets and blockchain technology.Strong communication and presentation abilities.Self-motivated, proactive, and capable of working independently.Ability to learn quickly and adapt in the fast-paced Web3 environment.Keywords for Candidate SearchWeb3 Data Analyst, Blockchain Data Analyst, Crypto Data Analyst, On-Chain Analyst, SQL, Python, Dune Analytics, Flipside, Nansen, Glassnode, BigQuery, EVM, Ethereum, DeFi, Tokenomics, On-Chain Analytics, Blockchain Analytics, Data Visualization, Tableau, Power BI, Web3 Research, Crypto Research.
Payment in Crypto
SADR B
Founding Technical Partners for Oferli – Elite Web & Mobile Development Team🌐
Remote, USA
Remote, USA
Part time
Remote
I am Sadr, CEO of Oferli. We are building a high-performance, elite technical team, and I am looking for 5 to 10 dedicated founding technical partners to join me in this mission.
The Vision:
Oferli is a 100% decentralized ecosystem. While we are rooted in Web3, our expertise spans across professional web and mobile application development. We are not just another agency; we are crafting the next generation of digital solutions. Our goal is to set a new standard for excellence, transparency, and decentralization.
What I am looking for:
I am building a professional, senior-level "Elite Team." I am looking for partners who are truly passionate about the vision—not just short-term gains. By combining our individual expertise and portfolios, we will establish Oferli’s collective professional reputation.
Requirements:
Proven Expertise: You must be a senior-level professional. Please provide your portfolio showcasing your best work in web and mobile development.
Commitment: This is a founding partnership. We are looking for those who believe in the mission and are ready to tackle complex challenges together.
Professionalism: We operate with high standards. Communication and efficiency are key.
How We Work:
Collaboration: We use professional, secure channels for all communications. Qualified candidates will be contacted via email to be invited to our private workspace on Notion to align on our roadmap and launch our upcoming projects.
Decentralized Operations: We leverage Web3 tools for collaboration and compensation, maintaining a fully decentralized environment.
Growth: We are launching with a core team of at least 5 founding partners, scaling to 10, to deliver high-impact results for our clients.
Application Process:
If you are a senior professional ready to build a world-class, decentralized ecosystem, apply here on LaborX. Qualified candidates will be contacted via email for further professional vetting and onboarding.
Let’s build the future, together.
Sadr B
CEO, Oferli
The Vision:
Oferli is a 100% decentralized ecosystem. While we are rooted in Web3, our expertise spans across professional web and mobile application development. We are not just another agency; we are crafting the next generation of digital solutions. Our goal is to set a new standard for excellence, transparency, and decentralization.
What I am looking for:
I am building a professional, senior-level "Elite Team." I am looking for partners who are truly passionate about the vision—not just short-term gains. By combining our individual expertise and portfolios, we will establish Oferli’s collective professional reputation.
Requirements:
Proven Expertise: You must be a senior-level professional. Please provide your portfolio showcasing your best work in web and mobile development.
Commitment: This is a founding partnership. We are looking for those who believe in the mission and are ready to tackle complex challenges together.
Professionalism: We operate with high standards. Communication and efficiency are key.
How We Work:
Collaboration: We use professional, secure channels for all communications. Qualified candidates will be contacted via email to be invited to our private workspace on Notion to align on our roadmap and launch our upcoming projects.
Decentralized Operations: We leverage Web3 tools for collaboration and compensation, maintaining a fully decentralized environment.
Growth: We are launching with a core team of at least 5 founding partners, scaling to 10, to deliver high-impact results for our clients.
Application Process:
If you are a senior professional ready to build a world-class, decentralized ecosystem, apply here on LaborX. Qualified candidates will be contacted via email for further professional vetting and onboarding.
Let’s build the future, together.
Sadr B
CEO, Oferli
Payment in Crypto
DracoinLabs
Senior Solana Blockchain Engineer
Full time
Remote
Senior Solana Blockchain Engineer (Rust / Anchor)
Compensation
Full-Time
$150,000–$250,000 USD/year
Contract / Consulting
$120–$200 USD/hour
Compensation is based on experience, technical expertise, production deployments, and project leadership.
About the Project
We are building the next generation of a Solana-based Web3 platform and are looking for a Senior Solana Blockchain Engineer to help architect and enhance an existing production project.
The current platform already includes:
Solana token implementation
Wallet integration
Core token functionality
The next phase includes:
Staking & reward distribution
DAO governance
Treasury management
Analytics dashboard
Security improvements
Performance optimization
Advanced Web3 infrastructure
This is a long-term opportunity for an experienced engineer who enjoys both architecture and hands-on development.
Responsibilities
Review the existing Solana architecture and codebase
Design and develop Solana programs using Rust and Anchor
Build staking and reward mechanisms
Design DAO governance systems
Develop treasury management features
Improve security, scalability, and testing
Collaborate with product and engineering teams
Produce technical documentation and architecture recommendations
Required Skills
5+ years of software engineering experience
3+ years of blockchain development
Strong Solana development experience
Advanced Rust programming
Anchor Framework
SPL Token Program
Smart contract security and testing
Production Web3 application experience
Git and collaborative workflows
Preferred Skills
Staking protocols
DAO governance
Treasury management
DeFi protocols
NFT infrastructure
Wallet integrations
DevOps / Cloud infrastructure
Smart contract auditing
Open-source blockchain contributions
Initial Engagement
The first milestone focuses on reviewing the existing platform and delivering:
Architecture review
Security assessment
Technical roadmap
Staking architecture proposal
Governance framework
Technical documentation
Successful completion will lead to long-term development work.
Hiring Process
Initial discussion
GitHub & portfolio review
Technical interview
Paid architecture review milestone
Long-term engagement
To Apply
Please include:
Resume / CV
GitHub profile
Portfolio
Solana project experience
Rust & Anchor experience
Examples of staking, DAO, NFT, or DeFi projects
Availability and preferred engagement type
Engagement
Remote
Full-Time or Contract
Long-Term Opportunity
If you're passionate about building scalable Solana infrastructure and production-grade Web3 applications, we'd love to hear from you.
Compensation
Full-Time
$150,000–$250,000 USD/year
Contract / Consulting
$120–$200 USD/hour
Compensation is based on experience, technical expertise, production deployments, and project leadership.
About the Project
We are building the next generation of a Solana-based Web3 platform and are looking for a Senior Solana Blockchain Engineer to help architect and enhance an existing production project.
The current platform already includes:
Solana token implementation
Wallet integration
Core token functionality
The next phase includes:
Staking & reward distribution
DAO governance
Treasury management
Analytics dashboard
Security improvements
Performance optimization
Advanced Web3 infrastructure
This is a long-term opportunity for an experienced engineer who enjoys both architecture and hands-on development.
Responsibilities
Review the existing Solana architecture and codebase
Design and develop Solana programs using Rust and Anchor
Build staking and reward mechanisms
Design DAO governance systems
Develop treasury management features
Improve security, scalability, and testing
Collaborate with product and engineering teams
Produce technical documentation and architecture recommendations
Required Skills
5+ years of software engineering experience
3+ years of blockchain development
Strong Solana development experience
Advanced Rust programming
Anchor Framework
SPL Token Program
Smart contract security and testing
Production Web3 application experience
Git and collaborative workflows
Preferred Skills
Staking protocols
DAO governance
Treasury management
DeFi protocols
NFT infrastructure
Wallet integrations
DevOps / Cloud infrastructure
Smart contract auditing
Open-source blockchain contributions
Initial Engagement
The first milestone focuses on reviewing the existing platform and delivering:
Architecture review
Security assessment
Technical roadmap
Staking architecture proposal
Governance framework
Technical documentation
Successful completion will lead to long-term development work.
Hiring Process
Initial discussion
GitHub & portfolio review
Technical interview
Paid architecture review milestone
Long-term engagement
To Apply
Please include:
Resume / CV
GitHub profile
Portfolio
Solana project experience
Rust & Anchor experience
Examples of staking, DAO, NFT, or DeFi projects
Availability and preferred engagement type
Engagement
Remote
Full-Time or Contract
Long-Term Opportunity
If you're passionate about building scalable Solana infrastructure and production-grade Web3 applications, we'd love to hear from you.
Payment in Crypto