株式会社ミツモアの【Eng-023】Senior Security Engineerの求人

ミツモアのミッション / Our Mission

「日本のGDPを増やし 明日がもっといい日になる と思える社会に」

労働生産性が先進国の中で低く、GDPも実質賃金も下がり続けている日本。
その閉塞感を打破するために、ミツモアはサービス産業の生産性向上を追求します。
まずは集客や見積もりを自動化するプラットフォーム「ミツモア」で、そして事業者のオペレーションの全てを効率化するSaaS「プロワン」で、さらに「プロワン」のインフラ環境と「ミツモア」で活躍する豊富なプロネットワークを掛け合わせた受発注DXサービス「ハッチュー」で。
サービス・プロダクトの利用者は急激に増えていますが、それでも目指す所へはまだ一合目。
途方もなく高い山だからこそ同じ想いを持ち、ユーザーやプロダクトにまっすぐに向き合える仲間と一緒にのぼりたい。
私たちと一緒に、世界基準のサービスを通じて、明日はきっといい日になると信じられる世の中を実現していきましょう。

About the position

As a senior security engineer at MeetsMore, you'll join the SRE team and cover four areas: penetration testing of our own products, application security in the development process, AI security—covering both our LLM-powered features and our AI-assisted development process—and the technical side of security compliance: implementing controls, automating evidence collection, and answering the engineering questions in audits and customer security checks.

You will be building the security team and leading the security effort across the company. You'll work alongside an SRE / DevOps team that automates as much as possible. Communication is mostly in English and occasionally in Japanese, with support from translation tools.

Our Tech Stack

Not exhaustive, but the most important are:

• TypeScript everywhere.
• NodeJS.
• React.
• MongoDB.
• AWS (Specifically ECS, CloudFront, S3, SQS, Lambda)
• Vercel.
• Redis.

Requirements

• Have built or improved security in a development process: threat modeling, design reviews, and security tools in CI/CD (SAST, DAST, dependency scanning).
• Experience with cloud infrastructure security: finding and fixing issues in AWS IAM and network configuration, Kubernetes (RBAC, network policies, workload permissions), and CI/CD pipelines (secrets handling, supply chain).
• Experience implementing and operating automated attack detection and protection using technologies such as WAF, IDS/IPS, runtime application security, or SIEM—including rule tuning, monitoring, alerting, and response to attacks such as SQL injection and XSS.
• Experience in securing Node.js based application (Python or Go for tooling is fine too, but TypeScript is preferred.)
• Either be conversational in Japanese or have a desire to do so (we will help).
• Be located in, or be willing to relocate to, Japan (we will relocate).

Nice to haves

• Experience testing or securing LLM-based features: prompt injection, jailbreaks, data leakage, or agent tool permissions.
• Have led at least one full penetration test from start to finish — scoping, testing, reporting, and confirming fixes — against web applications, mobile apps, and APIs.
• Have led a full certification audit (e.g., ISO 27001 / ISMS), ideally at a Japanese company: getting the controls in place, collecting evidence, and working directly with auditors.
• Offensive security certifications (OSCP, OSWE) or bug bounty / CTF experience.

Compensation

7 to 11 million JPY annually.