Senior Fullstack Engineer

Remote OK - Worldwide
Full-time
October 13, 2023

About the position

We are looking for senior engineers comfortable working with full-stack. You will primarily work with Ruby, building out features using Ruby on Rails and Typescript with Vue.js. As our platform is growing rapidly, you will help us build our platform to handle payments on a global scale.

As a senior developer you will need to work with our business analysts to define requirements and convert that into a usable architecture to discuss with colleagues. As hiring and supporting new developers is important to us you will be expected to be able to mentor junior developers, and work with them to improve their core skills.

Our ideal candidate has experience working with large web applications. They will know how to build reliable, scalable, and performant web applications. Testing and code quality are also extremely important to us, so having a strong knowledge of testing and the different testing types is required.

Responsibilities

Understand product goals and feature requests and translate them into working software
Support team members through code review and architecture discussions
Write tests that validate the stability and correctness of implementations
Mentor junior developers and help them grow their skills
Handle refactorings with both bravery and care

Requirements

Experience with building performant and scalable APIs, including DB performance
Experience with integrating with third party APIs in a secure and fault tolerant manner
Experience and understanding of common web exploits and how to mitigate them
Generalist (T-shaped developer), able to jump between frontend and backend code
Strong understanding of OOP programming languages and patterns

Salary

8,000,000 - 11,000,000 yen / year
Includes (rough estimate of) profit share. Based on experience and skill level

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About KOMOJU

KOMOJU (by Degica) is the leading cross-border payment gateway for Japan.

KOMOJU powers payments for leading companies, including the video game distribution platform Steam and the popular mobile app TikTok. Today, the company supports thousands of merchants by providing robust payment infrastructure—ranging from developer-friendly APIs to integrations with widely-used platforms like Shopify and Wix—enabling businesses to scale effectively in new markets.

In terms of engineering, KOMOJU fosters a developer-centric and inclusive culture. The team is committed to continuous improvement through regular self-evaluation and values individuality, recognizing the unique strengths that each engineer brings to the organization.

As KOMOJU grows, its development processes evolve accordingly. The engineering culture is largely self-organizing, with each engineer enjoying significant ownership over their projects. This environment empowers engineers to showcase their strengths while continuing to develop professionally.

Japanese Language Policy
With around half of KOMOJU’s total members (and around 90% of engineers) coming from outside Japan, teams generally use English for written communication(e.g. Slack, Github).

Verbal communication is also primarily in English.

However, quite a few people can speak both English and Japanese fluently, so Japanese may be spoken at times during meetings, especially when they involve teams other than engineering.

Overall, the language spoken depends on the team. The dev team uses mostly English, but the HR team (for example) speaks primarily Japanese.
Visa Sponsorship
KOMOJU sponsors visas for candidates living outside of Japan. KOMOJU also helps out with relocation (searching for apartments etc.) but they don’t have a formal policy for this. The support offered depends on each individual case. They do always pay for flight tickets to Japan in the case that someone moves from abroad.
Paid Leave
KOMOJU offers a generous vacation policy. In line with standard practices in Japan, employees begin with 10 days of paid time off (PTO) in their first year, with the number increasing in subsequent years based on Japanese labor law.

In addition to this, KOMOJU provides 5 extra vacation days during the summer and another 5 days for year-end holidays.

Employees also receive a day of birthday leave each year. Altogether, this adds up to 21 vacation days annually, not including Japanese public holidays. KOMOJU also offers maternity leave, paternity leave, and sick leave.
Benefits
💻 New tech gear

👩‍🎓 Skill development support

💛 Support for attending conferences

📕 Learning Budget

👶 Parental Leave

👩‍🏫 Language Learning Support

💜 Social security / insurance benefits included

🏥 Healthcare insurance

💚 Pension insurance

🚃 Commuter allowance

🛂 Visa and PR sponsorship

👍 Motorized sitting / standing desks when working from the office

🍱 Free office lunch twice a week
Engineer Interview Process
Engineering Roles

KOMOJU aims to keep their hiring process thoughtful and efficient. Typically, it involves 3–4 stages depending on the role:
- Initial Screening
- Take-home Exercise
- Technical Interview (Team Interview)
- Final Interview with Leadership
Throughout the process, the team evaluates technical skills and looks for alignment with team culture and potential for long-term growth.
Work style
KOMOJU operates as a remote-first company while placing a strong emphasis on personal connections and close collaboration. The company maintains an office in the Kichijoji area of Tokyo, which employees are welcome to visit for in-person collaboration and company events, such as weekly lunches provided at no cost.

Team members have the flexibility to work from anywhere within Japan, as well as up to three months per year from abroad. KOMOJU also offers flexible scheduling, allowing employees to set their own hours as long as they are available during the company’s core hours, Monday to Friday from 10:00 to 15:00 JST.