Solidity Developer (Remote)

SORAMITSU is an award-winning global financial technology company with expertise in developing blockchain-based solutions for digital asset and identity management. Our mission is to use blockchain to promote innovation and solve pressing societal challenges.

SORAMITSU is the developer of and major contributor to the open-source blockchain platform Hyperledger Iroha, which is tailored for enterprise and public-sector use. Hyperledger Iroha, a project of Hyperledger Foundation, part of the Linux Foundation, has a permissions system that is scalable and performant.

Utilizing blockchain, SORAMITSU has developed a digital currency for the National Bank of Cambodia, a CBDC Proof-of-Concept with the Bank of the Lao PDR, a closed-loop payment system for the University of Aizu in Japan, an identity verification system prototype for Bank Central Asia in Indonesia, we were finalists in the Monetary Authority of Singapore CBDC Challenge, and are currently participating in Asia-Pacific's first proof-of-concept test of a cross-border, multi-currency security settlement system using distributed ledger technology with the Asian Development Bank. We have also conducted proof-of-concept tests for several major Japanese enterprises, and are active contributors to open source projects, such as Klaytn, South Korea's leading Layer-1 blockchain, KAGOME, the C++ Polkadot Host implementation, the SORA crypto-economic system, the Polkaswap DEX, and the DeFi wallet, Fearless Wallet

Based on these experiences, SORAMITSU aims to deploy cutting-edge technology on a global level in order to expedite financial inclusion and health, mitigate economic inefficiencies, and contribute to the fulfilment of the Sustainable Development Goals.

You can find out more by visiting our homepage at soramitsu.co.jp or check out our Twitter profile.

We are seeking a highly skilled blockchain developer with deep expertise in blockchain technologies and smart contract development, focusing on Solidity, Ethereum, and various Layer 1 and Layer 2 protocols. This role will involve designing, implementing, and optimizing secure and scalable blockchain solutions.

You will be responsible for:

• Develop, deploy, and maintain secure, efficient, and scalable smart contracts on Ethereum and other blockchain networks.
• Architect decentralized systems and define smart contract standards for new projects and features.
• Lead code reviews and provide mentorship to junior and mid-level developers.Optimize smart contract code for gas efficiency, performance, and security.
• Collaborate with cross-functional teams including frontend developers, product managers, and security experts.Identify and mitigate security risks within smart contracts.
• Stay up-to-date with the latest trends, tools, and best practices in Solidity and blockchain development.
• Perform rigorous testing and auditing of contracts, and ensure all code is secure and bug-free.
  
  
  

Requirements:

• 3+ years working specifically with Solidity and Ethereum-based development.
• Fluent English
• Deep understanding of Ethereum's architecture, smart contracts, and related technologies.
• Proficient in Solidity, Web3.js, and Ethers.js.Experience with deploying and interacting with smart contracts on Ethereum, Binance Smart Chain, or other EVM-compatible blockchains.
• Familiarity with common design patterns (e.g., ERC-20, ERC-721, ERC-1155) and decentralized protocols.Expertise in smart contract security practices, including common vulnerabilities (e.g., reentrancy, overflow/underflow, front-running).
• Knowledge of decentralized finance (DeFi) protocols and their smart contract ecosystems.
• Experience with testing frameworks (e.g., Truffle, Hardhat, Foundry).
• Experience with CI/CD pipelines and blockchain-specific deployment strategies.
• Ability to communicate complex technical concepts effectively to both technical and non-technical stakeholders.
• Strong problem-solving, debugging, and optimization skills. Preferred:
• Experience in developing for Layer 2 networks or alternative blockchain protocols (e.g., Optimism, Arbitrum, Polygon).
• Familiarity with cross-chain technologies and bridging protocols.
• Experience with smart contract auditing tools like Slither, MythX, and others
  
  
  

General Skills:

• Programming Languages: Solidity, JavaScript, Python, with knowledge of Rust considered a plus.
• Blockchain Platforms: Ethereum, Binance Smart Chain, Polygon, Arbitrum, Optimism, etc.
• Frameworks & Libraries: Truffle, Hardhat, Foundry, Web3.js, Ethers.js.
• Security Best Practices: Smart contract auditing, vulnerability mitigation, best practices for gas optimization.
• Collaboration Tools: Git, GitHub/GitLab, JIRA, Slack, etc.
• Soft Skills: Strong communication in English, problem-solving, and analytical thinking.
  
  
  

Additional Requirements:

• Please include a link to your GitHub profile showcasing examples of your code or repositories where you’ve contributed.
  
  
  

What we offer:

• A relaxed remote-first (work from anywhere) work environment with flexible working hours
• A permanent, full-time role with a rapidly growing international team of professionals
• An educational budget to support your continued growth and development
• Opportunities to attend global meetups and conferences for learning and/or speaking engagements
• An opportunity to be a part of an award-winning team designing a better world through decentralized technologies
  
  
  

This is a remote position. Our distributed team is mostly spread across Europe and Asia. Team meetings are held generally during European working hours, and it is expected that you would adapt if necessary and be available accordingly.

If you have the required qualifications and are passionate about the Web3 industry, we encourage you to apply for this exciting opportunity.

SORAMITSU values diversity and is committed to providing equal opportunities for all applicants and employees. Our employment decisions, such as hiring, promotion, discipline, and termination, are based solely on an individual's qualifications, performance, and business needs. We do not discriminate against anyone on the basis of their race, color, religion, marital status, age, national origin, ancestry, physical or mental disability, medical condition, pregnancy, genetic information, gender, sexual orientation, gender identity or expression, veteran status, or any other protected status under federal, state, or local law.