Software Engineer, Backend

Tokyo, Japan · Engineering · EN/JP


Mercari's Backend Team is currently entering a major transition phase as part of the company's efforts to fulfill our mission of "creating value in a global marketplace where anyone can buy & sell.” The Mercari app has been growing at an incredible pace ever since its release and is now the largest C2C platform in Japan. The Mercari API codebase has also expanded in line with the service's growth and the variety of challenges faced. As we anticipate our service to grow at an even greater speed in the future, we are aiming to use microservices to help achieve Mercari JP's mission.

Although the Mercari API was designed and implemented as a monolithic API, we are working on migrating the API to microservices. This will allow us to divide responsibilities and make technological investments for a stronger system and organization capable of handling even greater expansion. Of course, we will continue to run our services as we implement these changes, and we aim to make daily improvements to provide an even better experience for our customers. Our backend engineers are expected to uphold the values “Go Bold” and “All for One” as they work to transform our systems and organization and contribute to our service's growth.

We are seeking backend engineers who can work proactively and independently during the team's current stage, taking ownership over various discussions, developing features, providing spec feedback, and making technical decisions.


これまでモノリシックなAPIとして設計・実装されてきたメルカリAPIをMicroservice化することで、責任範囲を分割し、より拡大に強い形のシステム・組織へと作り変える技術投資をしています。ですがもちろん、これを進める間もサービスの歩みは止まりません。お客様により良い体験を提供するため、日々の改善も進めていきます。バックエンドエンジニアには、システム・組織の大きな変革とサービスの成長の両面に対して、GoBold/All for oneに取り組むことが求められます。


▼Job Description

・Design, development, and operation of Mercari's API and web app using Go and PHP

・Design, development, and operation of tools to support the customer support team and planning-related work

・Design, development, and operation of various microservices making up the Mercari API

・Lead the team's development







▼Minimum Qualifications

・Experience with design, development, and operation of web applications using Go, Java, JavaScript

・Test definition skills using unit test frameworks

・Knowledge of and experience with query creation and table design for the efficient usage of RDBMS

・Experience with team development using Git/Github or similar version management systems

・Ability to design, develop and operate large-scale services while considering load

・Experience with project management and/or team leadership


・Experience developing and operating using microservice architecture

・Experience with on-call support for a service

・Experience developing apps using gRPC protocol

・Experience developing web app frameworks, libraries, etc.

・Knowledge of web app security

・Experience with development using external APIs such as payment, delivery, etc.

・Experience sharing and contributing to an OSS project

▼Technical Environment

・Languages: Go,PHP,JavaScript, etc.

・Middleware: MySQL, Memcached, Nginx, Solr, Docker, Kubernetes, etc.

・Infrastructure: Dedicated servers, Google Cloud Platform

・Other tools/services: Slack, JIRA, GitHub, Circle CI, etc.


・Go, Java, JavaScriptによるWebアプリケーションの設計・開発・運用経験


・RDBMSを効率的に利用するためのテーブル設計 / クエリ作成の知識・経験

・Git / GitHubもしくは類似のバージョン管理システムを利用したチームでの開発経験












・開発言語: Go,PHP,JavaScriptなど

・ミドルウェア: MySQL, memcached, Nginx, Solr, Docker, Kubernetesなど

・インフラストラクチャ: 専用サーバ, Google Cloud Platform

・その他利用ツール・サービス: Slack, JIRA, GitHub, Circle CIなど


▼Contract Type


 Probationary Period: 3 months (salary same as above)



▼Work Hours

・Fixed working hours 10:00-19:00

 Flex time (core hours 12:00-16:00, 60 minute lunch)


・Annual salary, paid monthly

・Based on your experience, skills and potential

・Reviewed twice a year


・5-day work week (Sat/Sun off)

・National holidays, paid time off, summer/New Year's vacation, congratulatory leave, compassionate leave








 フレックスタイム制度あり(コアタイム:12:00~16:00 [休憩60分] )









・Health insurance

・Incentive program

・Employee stock ownership plan

・Full transportation coverage

・Custom PC

・Dual screen if needed

・Company smartphone

・Visa support

・New Employee Benefits at Mercari「mercibox












Mercari Engineering Blog


About C to C marketplace mercari(English)

About Mercari, Inc(English)

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