Head of Security

Job Description

Director of Security / Head of Security

Location: Tokyo or Osaka, Japan | Hybrid Working

Annual Salary: JPY 11M-18M

Employment Type: Full-Time, Permanent

About The Opportunity

We are seeking an experienced Director of Security / Head of Security to establish and lead a dedicated Security Engineering function within a growing international technology company.

The organization has already established the foundations of its security program, including security policies, processes, and information security certifications. The next stage is to build a dedicated security organization capable of supporting business growth, strengthening product security, and addressing emerging cybersecurity challenges associated with AI-powered products and AI-assisted software development.

This is a strategic yet hands-on leadership opportunity for someone who can combine deep technical security expertise with organizational leadership and business understanding.

The successful candidate will have the autonomy to shape the security strategy, build the team, establish security processes, and work directly with senior engineering leadership.

Key Responsibilities

• Security Strategy and Team Leadership
• Develop and execute an organization-wide security strategy and roadmap.
• Establish security priorities, objectives, budgets, and resource plans.
• Build and lead a Security Engineering function from the ground up.
• Recruit, develop, and manage security engineering talent.
• Establish scalable security processes and operating models across global engineering teams.
• Evaluate security tools, vendors, and technology investments.
• Product and Application Security
• Drive Security by Design across product development.
• Establish threat modeling and secure architecture review processes.
• Integrate SAST, SCA, and secret detection into CI/CD pipelines.
• Lead vulnerability management and penetration testing programs.
• Establish and improve Secure Software Development Lifecycle (SSDLC) practices.
• Work closely with engineering teams to improve application and infrastructure security.
• AI / LLM Security
• Design security guardrails for AI agents, including permissions, tool execution, and data access.
• Develop and lead AI Red Teaming and adversarial testing initiatives.
• Identify and mitigate AI-related security threats, including prompt injection, jailbreaks, and tool misuse.
• Establish security policies for AI-assisted software development.
• Apply frameworks such as OWASP LLM Top 10 and MITRE ATLAS.
• Improve security operations through AI and automation.
• Governance, Risk, and Compliance
• Lead information security management and certification programs, including ISO 27001 and SOC 2.
• Establish security policies, standards, and internal controls.
• Conduct security risk assessments and oversee risk management activities.
• Develop data protection programs aligned with APPI and GDPR.
• Implement data classification, access control, masking, and tokenization practices.
• Collaborate with legal, compliance, and business stakeholders.
• Customer Security and Incident Response
• Lead enterprise customer security assessments, audits, and due diligence processes.
• Develop security documentation and customer-facing assurance materials.
• Engage with enterprise customers, external auditors, and regulatory stakeholders.
• Establish incident response frameworks and security monitoring capabilities.
• Lead technical decision-making and coordination during security incidents.
• Hands-on Technical Leadership
• Review security architecture, threat models, and technical designs.
• Participate in security tool development and technical evaluations.
• Assess cloud infrastructure and multi-tenant SaaS security.
• Review AI Red Teaming results and remediation plans.
• Provide technical guidance and mentorship to engineering teams.
  
  

Requirements

• 10+ years of professional experience in cybersecurity or information security.
• At least 3-5 years of experience leading security teams or programs within a software product or technology organization.
• Proven experience managing both Product Security and GRC functions.
• Strong Application Security experience, including SAST, SCA, vulnerability management, and penetration testing.
• Practical experience with ISO 27001, SOC 2, or equivalent security frameworks.
• Strong cloud security and DevSecOps experience, particularly AWS and CI/CD security integration.
• Experience implementing Secure SDLC practices within multi-tenant SaaS environments.
• Understanding of AI / LLM security threats and emerging AI agent risks.
• Familiarity with OWASP LLM Top 10 and MITRE ATLAS.
• Experience engaging with enterprise customers, auditors, and regulated industries.
• Hands-on experience with AI coding agents such as Claude Code or similar tools.
• Professional proficiency in Japanese and English, with fluency in at least one language and business-level communication skills in the other.
• Strong technical leadership, communication, and stakeholder management capabilities.
  
  

Preferred Qualifications

• Experience building a security organization from the ground up.
• Experience in regulated industries or enterprise technology environments.
• Strong understanding of APPI and GDPR.
• Experience leading SOC 2, ISO 27001, or PrivacyMark certification programs.
• Experience developing incident response and security monitoring capabilities.
• Experience managing security budgets, vendor selection, and investment decisions.
• Experience leading multinational and distributed engineering teams.
• Relevant certifications such as CISSP, CISM, CCSP, OSCP, GWAPT, or RISS.
  
  

Ideal Candidate

We Are Looking For a Security Leader Who

• Enjoys building security teams, processes, and capabilities from the ground up.
• Combines strategic thinking with hands-on technical expertise.
• Can translate complex technical risks into business priorities and actionable decisions.
• Understands how to balance security requirements with fast-paced software development.
• Is comfortable navigating emerging security challenges associated with AI and LLM technologies.
• Views security as a driver of customer trust, product quality, and business growth.
• Thrives in a dynamic, international, and evolving technology environment.
  
  

What the Opportunity Offers

• The opportunity to establish and lead a Security Engineering organization.
• Significant ownership of security strategy, hiring, budgeting, and technical direction.
• Direct collaboration with senior engineering leadership.
• Exposure to emerging AI security and AI-assisted development challenges.
• The opportunity to influence security practices across multiple products and global engineering teams.
• Potential career progression toward Global Head of Security or CISO.
  
  

Compensation And Benefits

Annual Salary: JPY 11,004,000-18,000,000, depending on experience and qualifications.

• Annual salary paid in 12 installments.
• Fixed overtime allowance covering 45 hours per month, with additional compensation for overtime exceeding this allowance.
• Commuting allowance.
• Full social insurance coverage.
• Hybrid working arrangement, with approximately one office day per week recommended.
• Flexible working hours, with core hours from 10:00-16:00.
• Company-provided laptop.
• Annual book and professional development allowance of JPY 55,000.
• Health checkups and health support leave.
• Childbirth and childcare support programs.
• Paid annual leave, summer holidays, and year-end holidays.
• Employee activities and team-building support.
  
  

Working Hours: 9:00-18:00.

Location: Candidates may choose between Tokyo and Osaka.

Employment Type: Full-Time, Permanent.

Probation Period: 3 months, with no change in employment conditions.

If you are an experienced security leader looking to build an organization, influence business strategy, and shape the future of AI security, this opportunity offers the scope and autonomy to make a significant impact.