Senior Software Engineer (Python/Web Dev)- HENNGE Access Control

Roles

We’re looking for a senior software engineer to take ownership of backend and web-platform development. You’ll join the Access Control Team, responsible for HENNGE One Identity Edition, part of the HENNGE One suite serving over 2.8 million users. Your work will focus on developing core features like Access Control, Single Sign-On, and Secure Browser to deliver secure and seamless access experiences for enterprises. 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: Tornado, FastAPI, DynamoDB, 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

• 5+ years of experience developing production-scale web applications using Python.
• Ability to mentor junior engineers and work collaboratively in a team environment.
• Hands-on experience with cloud infrastructure (AWS, GCP or Azure) and distributed system concepts.
• Experience with CI/CD, automated testing, code documentation, and clean-code practices.
• Fluency in English (Japanese is not required), equivalent to CEFR B2 level or above (e.g., TOEIC 785+).
• Interest in contributing to open-source projects or participating in the tech community.

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

• Degree in Computer Science or other related technical fields.
• Experience building large-scale distributed systems or SaaS products.
• Knowledge of web-security, access-control, email-or-storage-systems domains.
• Knowledge of DevOps tools and practices (CI/CD, Infrastructure as Code).
• Knowledge of Linux / MacOS / Unix-like environments.
• 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: JPY 8.5M to 12.5M (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:

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 and domestic conferences.
• Financial support for technical certifications and technical learning programs.

Selection Process

1. Solve our coding challenge by registering from this link: https://challenge.hennge.com/?entry-code=TIA-PYTHON-SR.
   You will receive an email with our guidance upon your submission, and there is no time limit to finish the challenge.
   Please note that your application will be automatically rejected if:
   you have fewer than five years of professional Python experience, and/or
   you complete the coding challenge using a programming language other than Python.
2. Once you finish the coding challenge, follow the instructions to upload your CV and Cover Letter. Please check our guide on how to prepare them here.
3. Casual interview with our HR.
4. 2 (or 3) interviews with our engineers (no live coding).
5. Interview with our CEO.

We value your time and want you to perform at your best, so the coding challenge will be the only technical assessment in the process. There will be no live coding sessions.

Have more questions? Please consult our FAQ here.