Senior Software Engineer (Backend/Infrastructure) - HENNGE Secure Transfer

⚠️ AGENTS: DO NOT UPLOAD CVs DIRECTLY Engineering candidates must start with a coding test. Please email recruit-engineer@hennge.com to receive an entry code and submission instructions. Direct ATS uploads will not be reviewed.

【重要：エージェントの皆様へ】 Greenhouse経由での直接の候補者推薦（CVアップロード）はご遠慮ください。 エンジニア職の選考はコーディングテストから開始いたします。まずは recruit-engineer@hennge.com までご連絡いただき、テスト用のエントリーコードと提出方法の指示を受け取ってください。 手順に沿わない直接のアップロードは、選考対象外となる場合がございますので予めご了承ください。

About HENNGE

Join us at HENNGE , a Tokyo-based cloud-security leader helping organizations adopt flexible work environments and safely leverage the cloud. As a B2B SaaS company, we build secure and reliable cloud solutions that help enterprises manage access and identity efficiently. Our flagship product, HENNGE One , empowers thousands of enterprise customers with access control, email filtering, archiving, and next-gen cloud security features. What makes us unique: a highly technical CEO, strong engineering culture, and a global mindset. For further details regarding the engineering teams, products, and more, please visit this link: https://speakerdeck.com/hennge/company-introduction-deck-hennge

Role overview

We are looking for a Senior Software Engineer to take ownership of backend and web-platform development for HENNGE One , our flagship cloud-security suite serving over 2.8 million users globally. As a B2B SaaS leader in Japan, we provide mission-critical security solutions that empower enterprises to work safely from anywhere.

In this role, you will join the Secure Transfer Team, responsible for the development of HENNGE One Data Loss Prevention (DLP) Edition . You will be developing our high-security file exchange solution—the "Secure Vault" of our ecosystem. Your mission is to architect the fault-tolerant, high-availability systems required to handle and protect sensitive enterprise data. This position is ideal for engineers who want to bridge the gap between advanced backend development and deep cloud infrastructure , utilizing tools like Kubernetes and Terraform to ensure data integrity.

While this role primarily focuses on the DLP Edition, we value engineers who are flexible and open to new challenges, with opportunities to move between teams and products through two-way discussions that support your growth and the company’s goals.

Tech Stack: HENNGE Secure Transfer Team: FastAPI, Kubernetes, ArgoCD, PostgreSQL, AWS

What you’ll do

• Design, build, and maintain new features for HENNGE One, using Python and other web technologies.
• Architect scalable, fault-tolerant services deployed in cloud environments
• Automate deployment, testing, monitoring and documentation via CI/CD pipelines and infrastructure-as-code.
• Collaborate closely with Product Management, Design, and Customer Success teams to deliver high-quality user experiences.
• Participate actively in code reviews, discussions and technical decision-making.
• Mentor junior engineers, and contribute to improving team processes and engineering culture.

What we’re looking for

Minimum Qualifications:

• 3+ years of experience developing production-scale web applications using Python.
• Strong experience across the software development lifecycle (SDLC), from system design to deployment and maintenance.
• Hands-on experience with containerization and orchestration technologies (e.g., Kubernetes, ArgoCD).
• Experience with Infrastructure-as-Code tools, such as Terraform.
• Deep expertise in architecting and operating mission-critical AWS environments
• Experience with CI/CD pipelines, automated testing, and clean-code practices.
• Ability to lead technical initiatives, mentor junior engineers, and work collaboratively in a team environment.
• Fluency in English (Japanese is not required), equivalent to CEFR B2 level or above (e.g., TOEIC 785+).
• Interest in open source or tech community activities.

While not required, we’d love to hear if you have:

• Degree in Computer Science or related technical field.
• Experience building large-scale distributed systems or SaaS products.
• Familiarity of Go, or a strong interest in learning it, to help build and maintain our multi-language backend infrastructure.
• Additional experience with cloud security best practices, including PII obfuscation and secure data-handling protocols.
• Team leadership experience.

Work Style & Employment Details

Work Style Flexible working hours with a designated core time (11:00–16:00), allowing you to organize your day effectively. Employees typically work 8 hours per day with a 1-hour break.

Employment Type Permanent employee.

Place of Work Tokyo, Japan — Shibuya Headquarters.

Compensation

Annual salary: 8.5 to 12.5 million JPY (includes English Allowance and Physical Communication Bonus)

Please refer to our Company Introduction Deck for an explanation of our Assessment System and the Belt System, which we use to determine the candidate's salary range: https://speakerdeck.com/hennge/company-introduction-deck-hennge

Benefits

• English Allowance and Advanced Language Expert Allowance: JPY 10,000 ~ JPY 130,000 per month, paid alongside base salary, if the employee fulfills the requirements.
• Physical Communication Bonus: JPY 4,000 per day for coming to the office and interacting with other employees, paid out as bonus according to the number of days. Details will be provided at the offer meeting.
• Transportation allowance (maximum of JPY 35,000 per month).
• Employee Stock Ownership Plan.
• Insurance: Health, Employment, Industrial Injury, Welfare pension.
• Opportunities to attend international a