Senior Solidity Engineer
Zürich, Switzerland
Full time
Remote
9,166.67
-
15,000
Monthly
110,000
-
180,000
Annual
Payment in Crypto
Role
Backend Engineer
Work Experience
From 1 to 3 years
Description
About the Role
We are seeking a Senior Solidity Engineer to design, develop, audit, and optimize high-performance smart contracts on Ethereum and EVM-compatible chains. As a senior contributor, you will lead critical protocol development, mentor junior engineers, and ensure our on-chain systems are secure, gas-efficient, scalable, and production-ready in a fast-moving Web3 environment.
Key Responsibilities
- Architect and implement complex smart contracts using Solidity for DeFi protocols, NFTs, governance systems, bridges, oracles, and other blockchain primitives.
- Conduct thorough security reviews, formal verification where applicable, and collaborate with external auditors.
- Optimize contracts for gas efficiency, security, and maintainability.
- Integrate smart contracts with front-end applications, off-chain services, indexing solutions (The Graph, Subsquid), and cross-chain infrastructure.
- Develop and maintain comprehensive test suites (unit, integration, fuzzing, and invariant testing).
- Participate in code reviews, architectural decisions, and technical roadmap planning.
- Mentor mid-level and junior engineers on best practices, security patterns, and Solidity internals.
- Monitor deployed contracts, respond to incidents, and implement post-deployment upgrades (via proxies where applicable).
- Stay current with EVM upgrades (e.g., Prague/Electra), L2 scaling solutions (Optimism, Arbitrum, zkSync, etc.), and emerging standards (ERC-xxx, Account Abstraction).
Required Qualifications (Must-Have)
- 1-3 years of professional experience in Solidity development with a proven track record of deploying secure, audited smart contracts to mainnet.
- Deep mastery of Solidity (v0.8.x+), including advanced patterns (reentrancy guards, upgradeable proxies – UUPS/Transparent, diamond pattern, libraries).
- Strong understanding of EVM internals, gas optimization techniques, and security vulnerabilities (SWC registry, common attack vectors).
- Proficiency with smart contract testing frameworks: Foundry (preferred) or Hardhat + ethers.js/waffle.
- Experience with formal verification tools (Certora, Slither, MythX) and static analysis.
- Solid experience in at least one major Web3 domain: DeFi (AMM, lending, derivatives), NFTs/marketplaces, RWA, or infrastructure (bridges, account abstraction).
- Strong TypeScript/JavaScript skills for tooling and integration.
- Experience working with Layer 2 solutions and cross-chain messaging protocols.
- Excellent written and verbal communication skills; ability to write clear technical documentation (NatSpec, architecture decision records).
- Track record of contributing to open-source projects or public GitHub repositories (please share links).
Preferred Qualifications (Strong Plus)
- Previous experience at a top-tier Web3 protocol, audit firm (e.g., Trail of Bits, OpenZeppelin), or high-profile DeFi project.
- Knowledge of Rust or other languages for blockchain development (bonus for familiarity with zk-proofs or Move).
- Experience with Account Abstraction (ERC-4337), intent-based architectures, or MEV mitigation.
- Familiarity with governance frameworks (Governor, Tally) and tokenomics design.
- Contributions to standards (EIPs) or participation in Ethereum core dev calls.
- Security researcher background or history of responsible disclosure.
What We Offer
- Competitive compensation (base + significant token equity).
- Fully remote-friendly with flexible hours.
- Opportunity to work on cutting-edge blockchain infrastructure with real user impact.
- Budget for conferences, security tooling, and continuous learning.
- Collaborative, high-trust engineering culture.
Skills Required
Rigel Swiss GmbH
Website
rigelswiss.comCompany size
Not specified
Location
Switzerland
Description
Not specified
David Rutkovsky
Chief Technology Officer (CTO) / Senior Full-Stack Developer (Web3)
London, UK
London, UK
Full time
Remote
About the Role
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
Payment in Crypto
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
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
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