Jobs in Japan
Explore hand-picked jobs in Japan for English speakers across tech, education, marketing, and more.
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Jobs in Japan
Explore hand-picked jobs in Japan for English speakers across tech, education, marketing, and more.
Vetted companies only. Apply from overseas.
MercariThis job posting was originally in Japanese. The English version is automatically translated. Please visit the company site for the most accurate information.
As a member of Mercari’s Security Engineering team, you will work on security design and process reviews, as well as building and deploying security measures and conducting penetration tests. Mercari security engineers have a unique role within the company, working on projects that affect the entire organization. Examples of responsibilities include monitoring, log analysis, and developing log infrastructure; conducting security reviews and creating threat models; designing and implementing security automation and dashboards; security testing of web and mobile applications; and project management. Under the guidance of senior engineers, you will participate in threat modeling, code reviews, and security testing to identify and mitigate risks in Mercari’s systems. You will develop and improve scripts to automate common security tasks, such as compliance checks, asset inventory integrity checks, and alert operations. You will conduct security research on specific topics, such as AI system security and supply chain risks, summarize key findings, and propose actionable improvements. You will support the vulnerability management process by triaging and validating security findings and coordinating remediation with developers. You will contribute to creating and updating internal documentation, including secure development guidelines, AI security best practices, security playbooks, and onboarding materials for engineers. You will also support security monitoring activities, including log analysis, tuning detection rules, and tracking misconfigurations and policy violations. The Threat Detection and Response Team develops and operates Mercari Group’s security monitoring, detection engineering, and incident response capabilities. To support rapid and scalable threat monitoring across the Group, the team handles a broad range of work, from collecting and managing security logs, codifying detections, automating processes with SOAR, and building AI-powered workflows to conducting hands-on investigations and manual response. The Platform Security Team develops and operates security controls and guardrails that protect Mercari’s global engineering platform. Its scope spans access management (GitHub, GCP, and PAM), CI/CD and Infrastructure-as-Code security, supply chain risk management, and Kubernetes security. Working closely with the Enterprise Security, Product Security, AI Security, and Infrastructure teams, the team embeds security into the software development lifecycle, enabling engineers across the Group to build and deploy securely at scale. The Product Security Team ensures that all customer-facing and internal applications are built securely throughout the development lifecycle and helps prevent vulnerabilities before products are released to production. The team conducts threat modeling, security architecture reviews, automated scanning, and penetration testing, and works directly with engineering teams to remediate defects. It also establishes secure coding standards, operates a vulnerability disclosure program, and builds automated security guardrails, creating an environment where developers can release features quickly without compromising security. The Enterprise Security Team develops and operates scalable security controls and guardrails to protect Mercari’s global workforce platform across identity, endpoints, major SaaS applications, and the corporate network. By incorporating zero-trust and defense-in-depth principles, the team creates a secure-by-default environment that minimizes security risks while improving productivity and enabling bold innovation across the Group. Mercari’s platform is built using modern cloud-native technologies such as GCP, Kubernetes, and Terraform, and is integrated with AI and automation tools. You will be able to tackle large-scale, complex security challenges involving the data and systems that support tens of millions of users. The company is pursuing new initiatives such as AI-driven development, zero-trust architecture, and secure by design, and encourages you to make suggestions, ask questions, and grow. Experienced security engineers will mentor you and support your hands-on learning and development. Mercari’s Security Engineering and Strategy teams work with vast amounts of data, logs, and dependencies. As a member of the team, you can take on unanswered questions while working with cutting-edge, complex cloud infrastructure systems. At Mercari, with its rapidly growing and expanding organization and services, automation is especially meaningful because it reduces reliance on manual work. We believe you will gain highly challenging experience by maintaining a fast pace while not only building security systems but also solving problems.
- Alignment with Mercari’s mission and values - Strong interest in cybersecurity and engineering - Development experience in at least one programming language, such as Go, Python, PHP, or JavaScript - Currently enrolled in a university program majoring in computer science, information security, or engineering (bachelor’s degree or higher), or in a vocational school - Excellent interpersonal and communication skills - Basic knowledge of Linux, including using common commands and scripts - Basic knowledge of SQL and data querying - English or Japanese proficiency at Independent level (CEFR B2)
- Basic knowledge of or strong interest in any of the following: participation in or speaking at Japanese events such as SECCON and the Hardening Project, or international conferences such as Black Hat and DEF CON - Practical experience participating in CTFs or bug bounty programs, or conducting penetration tests - Public cloud infrastructure platforms (GCP, AWS, Azure) - Container and orchestration technologies (Docker, Kubernetes) - Knowledge of security testing for web or mobile applications - Security automation and DevSecOps practices - Experience using AI to automate security operations or protect AI-driven systems - Basic experience using software development tools such as Git, dependency management, and build and deployment tools - Knowledge of modern web or mobile applications
