Protofire as great enthusiasts and active contributors to the open-source blockchain communities, we help builders and providers of decentralized infrastructure, protocols, and applications, bootstrap the demand and supply sides of their markets and accelerate mass adoption.

We help startups with protocol & smart contract engineering, high-performance trusted data feeds (oracles), and awesome developer tools (SDKs/APIs).

Since we started in 2016 we’ve had a chance to contribute to the development of many top projects in the blockchain ecosystem, including Maker, Chainlink, Tezos, Gnosis, Kyber Network, The Graph, Filecoin, Synthetix, Avalanche, and more. Apart from that, we are running one of the biggest indexer nodes in the Graph Network, participating as bridge relayers and validators helping projects and networks to further decentralize their infrastructure.

We are now looking to hire a cross-disciplinary team to help Protofire scale. As such, we’re looking for a Solidity Developer who’s had extensive experience writing, testing, deploying, and auditing smart contract code and who is up to date on the current developments in Solidity.

Besides knowing Solidity, we’d love to hear your informed opinion on the latest developer tooling, adhere to industry best practices, and follow the latest vulnerabilities and hacks in the Ethereum smart contract space with interest.

How you will make an impact:

• Produce high quality, performant, and well-tested Solidity code
• You’ll be working with advanced smart contracts, working on new features for the protocols, and creating new technical DeFi primitives
• Conducting technical due diligence and understanding dynamics/tradeoffs between different blockchain protocols
• Perform smart contract audits and identify vulnerabilities
• Work closely with the product team towards building out a DeFi application Integrating front ends with smart contract code
• Achieve comprehensive unit and integration test coverage
• Design and ideation of new functionality

What you need to succeed:

• 5+ years of experience in another programming stack or language
• 1+ years of Solidity smart contract development experience
• Understanding of Javascript Ethereum SDK’s (web3.js, ethers.js)
• Experience deploying Dapps or smart contracts on to Ethereum
• Smart contract dev tools/frameworks - hardhat and truffle
• Hands-on experience conducting smart contract audits, including identifying vulnerabilities, documenting findings, and providing recommendations for remediation.
• Familiarity with common attack vectors and auditing methodologies (e.g. reentrancy, front-running, integer overflows, gas optimization, etc.)
• CI/CD setup experience
• Deep understanding of the Ethereum Virtual Machine and the broad decentralized finance ecosystem
• Problem-solving attitude, ability to act autonomously, participate in discussions, and actively propose solutions.
• Excellent communication skills - You know how to work in teams, give and receive feedback, identify bottlenecks.
• A desire to keep up with blockchain technology trends and a real interest in decentralization

Apply Now:

Apply Now:

Serokell is a fast-growing, fully remote software development company that works on innovative solutions for complex problems. We’re packed full of adventurous, curious, and inclusive folks who want to build cutting-edge software with modern technologies like functional programming.

This position is open now with a July start. This is a project-based hire with the option to extend if it is a good match. Submit your CV and we’ll reach out promptly.

We’re seeking a middle to senior level Solidity Developer to join a team of fierce and fun Serokellers.

Hiring Process Overview: We invite candidates to the HR screening as the first step. Next, we conduct a technical interview with those whose profiles align with our requirements. Successful candidates will receive an offer.

Requirements:

• Fluency with Ethereum or another EVM-based blockchain ecosystem
• 2+ years in software development
• 1+ years experience writing, testing, and deploying Solidity contracts
• Hands-on experience with Hardhat, Foundry, Truffle, or Remix for development, testing, and debugging, including transaction submission, data retrieval, and key management
• Understanding of security issues and best practices for Ethereum and De-Fi applications
• Knowledge of popular token standards such as ERC-20, ERC-721, and ERC-1155
• Experience developing and integrating decentralized applications, both backend and frontend
• Basic understanding of cryptography primitives: public/private keys, signing, encryption, hashing
• Knowledge of fundamental algorithms and data structures like hash tables, binary search trees, DFS, quicksort
• Strong coding practices, including clean code structure, use of git, pull requests, and code review
• Fluent English, strong communication and collaboration skills
• Comfortable with daily stand-ups and asynchronous updates
• Self-driven, proactive, teamwork-oriented, curious and inclusive mindset
• Full-time commitment, around 140–160 hours per month
• Comfortable overlapping with team time zones from UTC 0 to UTC -8

It will be a significant plus if you have:

• Knowledge of TypeScript, Haskell, Rust, or OCaml
• Experience conducting security audits and identifying vulnerabilities
• Understanding of computer networks, HTTP, TCP/IP stack, and data synchronization models used in modern service APIs
• Familiarity with build/deploy automation tools and CI/CD systems such as Docker, Nix, Kubernetes

Responsibilities:

• Create and implement secure and efficient Solidity contracts, ensuring scalability, reliability, and maintainability
• Integrate contracts with EVM blockchain networks, often involving backend or frontend work
• Review and audit code
• Develop and execute unit tests, integration tests, and end-to-end tests
• Write detailed documentation for code, including design specs, user guides, and API documentation
• Stay updated on the latest developments in Solidity, Ethereum, and EVM-related technologies, cryptographic methods, and relevant programming languages
• Optimize code performance and gas efficiency
• Implement and enforce security best practices to protect contracts from common vulnerabilities
• Provide ongoing support and maintenance for deployed applications, addressing user-reported issues and bugs

We offer:

• Competitive salary.
• Engaging international projects.
• Participation in leading global conferences.
• International and multicultural teams.
• Fully remote work with flexible hours.
• Ability to take time off as needed.
• Investment in career and professional growth, with potential for wage increases.
• Mentoring and training programs.
• Opportunity to contribute to a leading functional programming blog.
• Therapy sessions for well-being support.

By joining Serokell, you’ll become part of a warm community of ingenious engineers, computer scientists, designers, marketing experts, and other inventive minds. You’ll work on ambitious projects building the next generation of computer software, explore creative initiatives unhindered by bureaucracy, and enjoy our vibrant Slack channels—ranging from #music to #philosophyandtears (did we mention the massive custom emoji set?).

Caiz

Revolutionizing Islamic Finance with Blockchain Technology

Are you ready to be part of a groundbreaking initiative that combines Islamic finance principles with cutting-edge blockchain technology?

Look no further than Caiz – The First Islamic Ecosystem Built on Blockchain

At Caiz, our mission is clear: to create a Fiqh compliant financial ecosystem that provides our community with fair and easy access to ethical financial products and services. We believe in empowering individuals to build a strong financial future while engaging in long-term economically beneficial behavior.

Our native coin, Caizcoin, that fuels the Caizblockchain. With Caizcoin, you can make seamless payments, store value, and interact with a range of ethical financial products we are developing. The centerpiece of our ecosystem is the innovative Caizapp, giving users complete control over their digital assets.

We are a passionate team reshaping finance, and we are expanding our dynamic workforce. Join us in a collaborative work environment focused on creating a fast and compliant money transfer structure.

Why to Join Caiz?

• Innovative & Purpose-Driven: At Caiz, we combine advanced blockchain technology with the principles of Islamic finance to create an innovative and modern financial system. Join us to be part of a forward-thinking organization that is reshaping the future of finance.
• Ethical Impact: As part of Caiz, you'll be working in an Organization that prioritizes ethics and integrity in all its operations, ensuring that every solution we offer aligns with the core values of fairness, transparency, and respect.
• Growth & Learning Opportunities: At Caiz, we value personal and professional growth. You'll have the opportunity to learn, innovate, and grow within a dynamic, supportive environment, while contributing to the development of ethical financial solutions.
• Global Vision, Local Impact: Caiz is focused on creating an inclusive, sustainable financial system that empowers individuals globally. You’ll be contributing to a company that has a positive impact on local communities and the global financial landscape.
• Collaborative Culture: We believe in teamwork and collaboration. You'll work alongside passionate professionals who are committed to driving change in the crypto and blockchain space, working together to create an ethical financial future.
• Secure & Transparent Environment: We emphasize trust and security in all aspects of our operations. As part of Caiz, you’ll be part of a transparent organization that values customer trust and ensures the highest security standards in the crypto space.

Tasks

We are looking for a highly skilled Blockchain Developer with expertise in Solidity and Rust to join our growing engineering team. You will play a key role in developing and optimizing smart contracts, blockchain protocols, and DeFi components that power the Caiz ecosystem.

As part of the core blockchain development team, you’ll work on both Ethereum-compatible smart contracts and Rust-based custom chain logic, contributing to secure, scalable, and innovative blockchain infrastructure.

Responsibilities:

• Design, develop, and deploy smart contracts using Solidity on EVM-compatible blockchains.
• Build and maintain Rust-based blockchain modules, such as on Substrate or Solana-compatible platforms.
• Contribute to the design of custom blockchain protocols and token standards.
• Write secure, gas-optimized, and thoroughly tested smart contracts.
• Collaborate with frontend and backend teams to integrate blockchain components into products.
• Conduct code reviews, audits, and vulnerability assessments for blockchain code.
• Analyze and improve the performance, security, and scalability of the Caiz blockchain.
• Stay up-to-date with the latest developments in blockchain technologies, including new EIPs, cryptographic primitives, and layer-2 solutions.

Requirements

Experience:

• 3+ years of experience in blockchain development with hands-on coding in Solidity and Rust.
• Strong understanding of smart contract design, blockchain architecture, cryptography, and consensus mechanisms.
• Experience developing and deploying smart contracts on Ethereum or similar EVM chains.
• Proficiency in Rust for blockchain environments such as Substrate or Solana.
• Familiarity with Web3.js, Ethers.js, Hardhat, Truffle, and related tools.
• Understanding of DeFi protocols, token standards (ERC-20, ERC-721, etc.), and layer-1/layer-2 ecosystems.
• Experience with version control systems (Git) and CI/CD workflows.
• Strong problem-solving skills and ability to write clean, maintainable code.

Preferred Skills

• Experience in building or contributing to a Layer 1 or Layer 2 blockchain.
• Knowledge of blockchain security best practices and audit processes.
• Exposure to zero-knowledge proofs (ZK), rollups, or cross-chain bridges.
• Experience in working within agile or startup environments.
• Understanding of Islamic finance or Sharia-compliant financial principles is a plus.

Level of studies: Bachelor’s degree in Computer Science, Software Engineering, Mathematics, or a related technical field.

Language Requirements: Fluent in English

Benefits

Benefits at Caiz:

• Competitive Financial Compensation: We offer financial benefits that reflect the value of your work and dedication.
• Work Flexibility: Enjoy the flexibility to work from home, the office, or even abroad.
• Annual Holidays: Generous paid time off to help you maintain a healthy work-life balance.
• Relocation Assistance: We provide relocation support for employees moving to new locations.
• Professional Development: Opportunities for training, certifications, and career growth.
• Employee Recognition: Programs to celebrate and reward your achievements and contributions.
• Inclusive & Collaborative Culture: A supportive and diverse work environment where your voice matters.
• Diversity, Equality, and Inclusion: We are committed to fostering a workplace that values diversity and promotes equality and inclusion for all employees.

Don't miss this opportunity – apply now and be part of the Caiz revolution.

Apply Now: