Tokyo, Tokyo Startale Group

About the Role
You will be a senior contributor within our smart contract engineering team, working closely alongside other engineers, product partners, and stakeholders to build the core systems that power high-value decentralized financial applications. This includes work on
stablecoin systems, liquidity infrastructure, and broader DeFi protocols
, among other emerging on-chain financial products.

You'll design secure, scalable, and composable smart contracts used in production environments, help shape protocol architecture, and ensure a consistently high standard of security, reliability, and performance across everything the team delivers. You'll collaborate deeply within the team to bring new on-chain ideas from concept through deployment and continuous improvement.

Key Responsibilities
Protocol Architecture & Technical Contributions

  • Contribute to the evolution of protocol architecture, contract design patterns, and security best practices
  • Make thoughtful technical decisions around performance, composability, and risk

Smart Contract Development

  • Design, implement, and maintain advanced Solidity smart contracts using Foundry
  • Build production-grade systems focused primarily on DeFi use cases and high-value financial logic
  • Support deployment and lifecycle management across multiple networks

Security, Testing & Reliability

  • Build comprehensive unit, integration, fuzzing, and fork testing suites
  • Debug complex on-chain systems using traces, simulations, and low-level diagnostics
  • Ship audit-ready, production-quality contracts that meet high security standards

Ownership & Execution
Own and deliver end-to-end contract development work streams, including:

  • Core protocol components and upgrades
  • High-risk, security-sensitive financial logic
  • Ongoing maintenance and improvements of deployed systems

Collaboration

  • Work closely with Product and Backend engineering teams as an active team member to refine requirements and deliver outcomes
  • Contribute to specifications, documentation, and team design discussions

Qualifications
Required Experience

  • 4+ years
    of professional software engineering experience, with strong emphasis on prototyping and new product development
  • 3-5+ years of Solidity development experience
    , with proven production delivery of audited smart contracts
  • At least 2 mainnet deployments, ideally powering widely used or financially meaningful applications
  • Extensive experience with EVM smart contracts and DeFi-centric development
  • Strong proficiency with Foundry or similar frameworks
  • Solid understanding of protocol mechanics, gas efficiency, performance, and security fundamentals
  • Familiarity with common vulnerability classes and best-practice mitigations
  • Proven ability to debug complex systems using traces and simulations
  • Comfortable working collaboratively within a team in fast-moving and ambiguous environments
  • Excellent written and verbal communication skills

Nice to Have

  • Experience participating in or responding to security audits; or writing audit-ready specs
  • Experience working on stablecoin projects, with strong understanding of how pegs are designed and maintained; familiarity with other DeFi primitives such as lending or DEXs is a plus.
  • Practical understanding of composability risks and protocol integrations
  • Experience working on widely used protocols or infrastructure
  • Startup or scale-up environment experience

Location and Logistics
East Asia preferred (Tokyo, Singapore, Hong Kong)



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