Software Engineer - Mercari/Merpay (Internship)

  • Tokyo
  • Remote OK - Anywhere in Japan
  • Internship
  • January 12, 2024
Apply from Anywhere 👍
Relocation to Japan 👍
(Overseas visa sponsorship supported)
Language Requirements
Japanese: Not Required 👍
English: Fluent
Minimum Experience
New Grad or above


Circulate all forms of value to unleash the potential in all people

"What can I do to help society thrive with the finite resources we have?" The Mercari marketplace app was born in 2013 out of this thought by our founder Shintaro Yamada as he traveled the world. We believe that by circulating all forms of value, not just physical things and money, we can create opportunities for anyone to realize their dreams and contribute to society and the people around them. Mercari aims to use technology to connect people all over the world and create a world where anyone can unleash their potential. For more information about Mercari Group’s mission, see Mercari's Culture Doc.


Equal Opportunity Hiring

Here at Mercari, we work to realize a world in which no one’s potential is limited by their background and everyone has the opportunity to freely create value. We also firmly believe that a mindset of Diversity & Inclusion is essential for us to achieve our mission.

This, of course, extends to our hiring practices as well. Mercari is committed to eliminating discrimination based on age, gender, sexual orientation, race, religion, physical disability, and other such factors so that anyone who shares our mission and values can join us, regardless of their background. For more details, please read our D&I Statement.


Team’s Mission / Work Responsibilities

  • Interns will be tasked with developing features for the Mercari marketplace app in Japan, or the Merpay mobile payment service. Successful candidates will join a team of software engineers, who come from diverse backgrounds hold various expertise, and work as a member of their team.
  • The specific content of your work will involve projects to improve the UX and specifications of our products and make them more friendly for Mercari, Merpay, and Mercari Shops users. Currently, Mercari is implementing various initiatives including improving the search screen to enhance the listing and purchasing experience, and therefore you will be requested to actually handle our technology and data to produce output. At Merpay, we engage not only in B2B service development but also B2C service development, and you will have the opportunity to be involved in both.
  • At the end of the internship, you will report the content and actual results of your work at an event held for this purpose. You can find presentation materials produced by past interns in the following article on our owned media site, Mercan.


Group Companies Recruiting

In addition to Mercari, Inc., we are also looking for interns for Merpay, Inc. Please select the Group company you would like to intern for when applying (Mercari, Merpay, or no preference). Please also be sure to check the language requirements for each company.

  • Under the mission of “Building trust for a seamless society,” Merpay, Inc. aims to transform the way money flows throughout the world and make it possible for all kinds of services to be used simply and securely through a single platform.


Unique and Bold Challenges

  • During this internship, you will work to develop actual features integrated into the app and to improve the operation of the app. We hope that, by working in the same environment as our full-time members, interns will not only acquire new skills and immerse themselves in the company culture but also use the internship as an opportunity for self-reflection.
  • At Mercari Group, you will be able to take on bold challenges without any fear of failure. What’s more, you will be able to flexibly choose the latest and optimal technologies, and because we foster an environment and culture that supports independent decision-making, the experience will offer an opportunity for both personal and professional growth. 


Required Experience

  • Candidate must be a student over 16 years old
  • Experience in at least one of the following:
    • As for Merpay backend position, PHP or Go developing experience is required
    • Experience in web infrastructure operation using Kubernetes, Terraform, Go, Docker, GCP, Nginx, etc
    • Foundational knowledge of network protocols such as TCP/IP and HTTP
    • Experience developing and operating software using Go, PHP, Perl, Python, Ruby, or Node.js
    • Backend: Design, development, and operation of APIs using Go, PHP, or Java
    • Frontend: Development related to frontend fields such as web browsers, JavaScript, TypeScript, React, Next.js, or Redux
    • iOS: Development experience with Swift.
    • Android: Development experience with Kotlin.
    • Machine Learning: ML modeling or development experience with ML systems, fluency in Japanese.
    • Platform (click here for details)
    • QA: Experience writing any type of automated tests (unit, integration, E2E). Knowledge or Experience with functional testing techniques and exploratory testing.
    • SRE (click here for details)
  • Experience developing and operating products
  • Basic knowledge of RDBMS and SQL


Preferred Experience

  • Experience with project management and/or team leadership
  • Ability to design and develop with performance and scalability in mind
  • Knowledge of object-oriented software development, networking, and memory management.
  • Knowledge in software test including unit testing, functional testing, and e2e testing
  • Knowledge of and experience with networks, Linux servers, surveillance systems, logging, and system operation
  • Experience with development and operation in a microservices architecture
  • Cloud development experience (preferably GCP or AWS)
  • Understanding of UI development
  • OSS contribution experience / familiarity with OSS community
  • Experience with team development using Git or similar management systems


Language Requirements

  • English or Japanese: Independent (CEFR - B2)
    • In Merpay, there are cases where Independent (CEFR - B2)-level Japanese is required
    • In Mercari, there are cases where Independent (CEFR - B2)-level English Independent is required


Working Conditions

Employment Status




  • Roppongi (Tokyo, Japan)
    • Smoking is prohibited within our offices
    • Mercari has introduced a work style policy called “Your Choice.” Each member is free to choose whether they want to work in the office or work fully remote. *Exceptions made for certain kinds of work.


Work Hours

  • Able to work more than 20 hours per week
  • 3 months of Internship is encouraged. Please consult with the recruiter if you prefer shorter/longer period



  • Hourly wage (Salary: Negotiable)



  • Full transportation coverage
  • Custom PC
  • Visa support
  • Accommodation for those who are from outside of Tokyo area





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