Senior Security Engineer (Web3)

TL;DR

Senior Security Engineer (Web3): Leading the end-to-end security posture of products and infrastructure with an accent on cloud, Kubernetes, and smart contract security. Focus on threat modeling, vulnerability management, and securing AI-accelerated workflows within a high-impact crypto environment.

Location: Hybrid (Tokyo, Shibuya) or Remote

Company

A leading platform in the crypto and Web3 space, focused on building secure, scalable decentralized financial products.

What you will do

• Lead the design and implementation of security controls across AWS, EKS, and CI/CD pipelines.
• Own threat modeling, risk assessments, and security architecture reviews for infrastructure and AI-driven systems.
• Drive end-to-end vulnerability management across code, infrastructure, and AI-generated artifacts.
• Define and enforce secure coding standards and guardrails for LLMs and automated workflows.
• Build and operate security monitoring, alerting, and incident response capabilities.
• Partner with blockchain and product teams to mitigate risks in decentralized systems.

Requirements

• 5–8 years of experience in application, cloud, and infrastructure security.
• Strong understanding of Web3 security, including smart contracts and key management.
• Deep hands-on experience securing AWS and Kubernetes environments.
• Proficiency in AppSec, secure SDLC, and common security tooling like SAST/DAST and SIEM.
• Solid foundation in network security, cryptography, and authentication protocols.
• Experience with incident response, threat modeling, and compliance standards like SOC 2 and ISO 27001.

Nice to have

• Relevant certifications such as CISSP, OSCP, or AWS Security.
• Experience with DevSecOps, service mesh, or microservices security.
• Background in software engineering (Java, Rust, TypeScript).
• Smart contract auditing experience or familiarity with Web3 tooling.
• Professional fluency in Japanese.

Culture & Benefits

• High-impact role with direct visibility to engineering and company leadership.
• Ownership over a broad security mandate with the ability to shape strategy.
• Collaborative, engineering-first culture that prioritizes security.
• Opportunities for professional development, certifications, and conference attendance.