Senior Front-end Engineer (React)

  • Tokyo
  • Partial Remote
  • Full-time
  • April 8, 2024
7,500,000 - 12,000,000 JPY /yr
Apply from Anywhere 👍
Relocation to Japan 👍
(Overseas visa sponsorship supported)
Language Requirements
Japanese: Not Required 👍
English: Business Level
Minimum Experience
Mid-level or above


HENNGE is a B2B SaaS company based in Tokyo Japan, and we are at the forefront of the changing workplace. HENNGE One, one of Japan's top cloud security services, allows customers to adopt flexible work environments and safely harness the power of the cloud from any location. With cloud security ensured, employees can focus on working smarter, improving quality, and achieving business results.



We’re currently looking for a senior front-end engineer to join our fast-paced growing team.

As part of the engineering team, you will be responsible for building cloud-security solutions used by thousands of enterprise companies. Our flagship product, HENNGE One, provides functionalities ranging from access control, email filtering, online storage, and email archiving. We focus on implementing state-of-the-art security functionalities, ensuring SLA 99.9% in distributed fault-tolerant deployment, and providing the best user experience to our customers.



  • Design, develop, and maintain innovative features based on business needs
  • Bring our design system to life by implementing high-fidelity UI using a modern frontend framework
  • Ensure high-quality deliverables through CI/CD pipelines, tests, and documentation
  • Collaborate with Design, Product Management and Customer Success teams to continuously improve the product
  • Support the team by actively participating in discussions and reviewing others’ code
  • Improve team synergy and mentor junior engineers


Our Tech Stack

Each product team is free to choose their own tech stack. Each project uses Typescript as the base language, with a combination of these technologies:



  • Styled Components
  • Redux (Toolkit)
  • RxJS
  • Jest/Testing Library
  • Testcafe

For more information, you can also check our Stackshare page.



Minimum Qualifications

  • 3 years of web development experience, with at least two years in React
  • Ability to write proper type-safe code with Typescript
  • Ability to mentor junior engineers and work collaboratively in a team environment
  • Ability to write robust tests along with your code
  • Understand the importance of clean code and software documentation
  • Business-level English (Japanese is NOT required)
  • Interested in open source/tech community 


Nice to have

  • Degree in Computer Science or other related technical fields
  • Experience with state management in a complex web app (e.g. Redux, Vuex)
  • Familiarity with design collaboration tools like Figma
  • Knowledge of setting up build and test environments, CI/CD pipelines
  • Knowledge of Unix-like environment
  • Team leadership experience
  • React: experience with Hooks, css-in-js libraries



  • Flexible working hours with core time
  • Hybrid workstyle environment with emphasis on in-office collaboration and the encouragement for employees to work onsite



  • Language learning support (English/Japanese)
  • English allowance and Advanced language expert allowance
  • Insurance: Health, Employment, Industrial Injury, Welfare pension
  • Employee Stock Ownership Plan
  • Opportunities to attend international and domestic conferences
  • Financial support for technical certifications and technical learning programs
  • Office clubs to join: coffee club, board game club, karaoke club, language cafe club, etc.
  • Transportation allowance (maximum of 35,000yen per month)


Reasons why you will enjoy working at HENNGE

  1. HENNGE offers a diverse development team with people from over 20 countries who love technology and Japanese culture. Located in the heart of metropolitan Tokyo, HENNGE offers a non-traditional Japanese experience working in Shibuya, one of the busiest and most exciting places in the world.
  2. Work-life balance is highly valued at HENNGE, and lots of fun happens at our office! Weekly board game nights, seasonal in-house events, monthly technical sessions, attendance of international tech conferences, new business contests, and many more.
  3. Having our CEO as the CTO, we are driven to continuously explore and develop the latest technologies.

Check out Henry's story to see how front-end engineers at HENNGE work.


Selection Process

  1. Solve our coding challenge. (Click on "APPLY NOW")
  2. You will be receiving an email with guidance from us upon your submission.
  3. Upload your CV and Cover Letter
  4. Casual interview with our HR
  5.  2 (or 3) interviews with our engineers
  6. Interview with our CEO

* There's NO need to upload the Resume/CV and Cover letter. You will be asked to upload it later after solving the challenge.

Stuck on your cover letter? No worries! Get some tips from our recruiting team on what to include in your cover letter.


主には、クラウドサービスのセキュリティレベルを引き上げる「HENNGE One」などの自社サービスやITコンサルティングサービスを提供しています。

HENNGE One はMicrosoft 365、Google Workspace、Box、LINE WORKSなど複数のクラウドサービスへのセキュアなアクセスとシングルサインオンを実現するSaaS認証基盤です。IP制限、デバイス証明書、セキュアブラウザ、パスワードレス認証、多要素認証(MFA)など豊富な認証機能で利便性と安全性のバランスのとれたセキュリティサービスを提供します。



View HENNGE's company page

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Senior Front-end Engineer (React) at HENNGE