Senior Blockchain Developer

Cytric; Netherlands; Remote; EUR 70,000 - 110,000; Full time

Job summary

Cytric BV, a web3 consultancy, is seeking an experienced Solidity developer to lead smart contract work on client projects. You’ll be the blockchain expert on each assignment, delivering robust contracts for tokens, DeFi apps, and trading platforms.

You will write tests and deploy scripts, build tooling to interact with contracts, and document technical details for teams and users. Remote freelance contractor, project-based with flexibility to manage workloads.

Qualifications

• Deep understanding of smart contracts, including EVM, security, gas optimization, and best practices.
• Strong Solidity skills with real project experience.
• Knowledge of DeFi basics: ERC20/ERC721/ERC1155, DEXes, liquidity pools, staking.
• Ability to write thorough test suites using tools like Hardhat or Foundry.
• Nearly full-time availability (30-40 hours per week) and ability to work independently.
• Excellent communication to collaborate with backend, frontend, and designers.

Responsibilities

• Write smart contracts on EVM chains for tokens, platforms, and DeFi apps.
• Write tests and deploy scripts to ensure contracts work safely.
• Build tools to interact with and manage smart contracts.
• Write clear documentation for technical teams and users.
• Work with other developers to build complete applications.
• Lead the blockchain work as the sole smart contract developer on projects.

Skills

Smart contracts

Solidity

DeFi basics

Testing

Independent work

Full-time availability

Tools

Hardhat

Foundry

Job description

We need an experienced Solidity developer for our web3 agency. You'll build smart contracts for client projects. You'll be the blockchain expert on each project.

What You'll Do

• Write smart contracts on EVM chains (Ethereum, Polygon, BSC, etc.) for tokens, trading platforms, and DeFi apps
• Write tests and deploy scripts to make sure contracts work correctly and safely
• Build tools to interact with and manage smart contracts
• Write clear documentation for technical teams and users
• Work with other developers - backend, frontend, and designers - to build complete applications
• Lead the blockchain work as the only smart contract developer on projects

Who You Are

Must Have:

• Know smart contracts deeply - you understand the EVM, common security issues, gas optimization, and best practices
• Strong Solidity skills with real projects you can show us
• Know DeFi basics - tokens (ERC20, ERC721, ERC1155), DEXes, liquidity pools, staking, or other financial tools
• Know how to test - you write thorough test suites (Hardhat, Foundry, or similar tools)
• Nearly full-time availability - you can work 30-40 hours per week when projects are active
• Work independently - you're comfortable working on your own while staying connected with the team

Nice to Have:

• Experience with Solana (Rust/Anchor) or other chains (Move, Func, etc.)
• Security audit experience or security training
• Contributions to open source web3 projects
• Agency or client work experience

How You'll Work

• Freelance contractor - paid per project at a fixed price
• Project-based - busy during active projects, quieter between projects
• Work remotely - from anywhere, with some overlap for team calls
• Talk to clients sometimes

Why Join Us

• Work on different types of web3 projects
• Team up with skilled developers and designers
• Build your portfolio with real applications
• Good pay for your work
• Freelance flexibility with steady project flow