Senior Python Developer
Zielona Góra, Poland
Full time
Office
Compensation is not specified
Role
Software Engineer
Description
Company Overview:
B2C2 is a leading digital asset organization that focuses on revolutionizing the ecosystem through providing institutional access to the crypto market. With a foundation in cutting-edge technology and continuous innovation, B2C2 has established itself as a trusted partner for various global institutions. Since its establishment in 2015 and subsequent acquisition by SBI in 2020, B2C2 operates as an independent entity. Headquartered in the UK, the company has additional offices in the US and Japan, and is authorized and regulated by the UK’s Financial Conduct Authority (FRN 810834).
We take pride in our unique company culture and our ability to attract top talent and individuals who resonate with our values. If you are seeking an exciting opportunity in a vibrant industry and company, read on for further details.
Role Overview:
In this role, you will have the opportunity to tackle diverse challenges spanning various teams, allowing you to broaden your knowledge in multiple business domains. Your contributions will directly impact various stakeholders within the organization, aligning with strategic objectives and enhancing our technology stack. As a key member of the team, you will collaborate with different departments to understand project requirements, contribute to system design, and interface closely with developers and business stakeholders.
Key technologies utilized include Django, DRF, Celery, Python 3.11, AWS EKS, Amazon Aurora PostgreSQL, Amazon ElastiCache, and Amazon MSK.
Responsibilities:
- Develop and maintain effective Python-based applications and components with a focus on code quality and compliance with coding standards.
- Enhance and manage in-house Python shared libraries to ensure reliability and efficiency.
- Write robust, well-documented, and thoroughly-tested code to achieve project objectives within specified timelines.
- Troubleshoot software defects and technical issues to minimize disruptions in revenue-generating processes.
- Collaborate with cross-functional teams to define and implement new features.
- Participate in code reviews and incorporate feedback for continuous improvement.
- Maintain and enforce comprehensive internal documentation.
Required Skills:
- Minimum 8 years of Python software development experience.
- Proficiency in building, deploying, and managing scalable web applications.
- Deep understanding of relational databases, SQL, and web technologies and protocols.
- Strong coding practices with a focus on efficiency.
- Experience in writing automated tests and providing production support for critical services.
- Ability to take ownership of projects from inception to delivery.
- Effective communication skills in English and Polish (B2/C1 level).
Desired Skills:
- Familiarity with Django, DRF, Celery, PostgreSQL, Kafka, Redis, and gRPC.
- Some exposure to Linux, Docker, Kubernetes, and AWS.
- Interest in cryptocurrency and trading.
- Experience with ReactJS or front-end technologies.
Opportunity:
- Rapid growth opportunities and an environment that encourages continuous improvement.
- Work with cutting-edge technologies to maximize productivity.
- Develop your career within a growing organization specializing in finance technology.
- Be part of a forward-thinking company making a meaningful impact on the future of finance.
- Enjoy a dynamic work environment blending hard work and fun.
- Conduct bi-annual performance reviews and receive discretionary bonuses.
- Contribute to a forward-thinking and dynamic organization culture.
Equal Employment Opportunities Policy:
B2C2 promotes equal employment opportunities for all applicants and employees, irrespective of race, color, religion, sex, national origin, age, disability, genetic information, marital status, or any other characteristic protected by laws. We are committed to cultivating an inclusive work environment to attract and retain the best talent, and open to considering flexible work arrangements for all roles.
Skills Required
B2C2
Website
www.b2c2.comCompany size
Not specified
Location
United States
Description
Not specified
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
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
sanchez lucysta
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.
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