Software Engineer, Machine Learning [Internship]

Tokyo, Japan · Student Recruitment · EN/JP


(Japanese follows English)

▼ Our mission

We are always looking for new challenges to help us fulfill our mission to create value in a global marketplace where anyone can buy & sell.

The world is full of objects and services being produced and sold, but many of them are thrown away without people realizing that they might be valuable to someone else, wasting valuable natural resources. To contribute towards eliminating waste, we have launched Mercari, a marketplace where people can buy and sell easily and safely, in Japan and the United States.

Merpay’s mission is to build trust for a seamless society. Our aim is to change the way money is circulated, establish a Merpay that provides all kinds of services, and develop a world where everyone can enjoy peace of mind.

Merpay aims to bring liquidity and innovation to the world of finance, and create new value not just for consumers, but for businesses as well.

▼ Our three values (Go Bold, All for One, Be a Pro)

We work together to create a global marketplace, but the road to this goal is by no means easy. In order for us to make new innovations and take on new challenges that no one has taken before, all of us take ownership of our work and make use of our knowledge so that we can create the best product possible as one team. To achieve this, we all take action based on our three company values (Go Bold, All for One, and Be a Pro).

▼ The goal of the engineering organization

At Mercari, engineering teams always strive to continuously produce significant results. To do this, our organization constantly welcomes changes and new challenges, cooperates and co-creates, is diverse, offers freedom, and encourages all of us to take ownership and make our own decisions. We want to continue taking on new challenges, working together as one team, going bold, and taking ownership so that we can grow individually, while working toward the realization of Mercari’s mission.



世の中では多くのモノ・サービスが生産・販売されていますが、誰かには価値があるのに捨ててしまうなど地球資源の無駄になっていることが多いと私たちは考えています。 「捨てる」をなくすために、個人間で簡単かつ安全にモノを売買できるフリマアプリ「メルカリ」を日本とアメリカで展開しています。




▼ 3つのバリュー(Go Bold, All for One, Be a Pro)

世界的なマーケットプレイスを創るために我々は集まっていますが、この目標への道のりは決して平坦ではありません。まだ誰も挑戦したことのないようなイノベーションや破壊的な創造を起こすため、我々は各自がオーナーシップを持ち、専門的能力を発揮することで、メルカリというチームとして最高のプロダクトを創ります。これを達成するために我々は3つのバリュー(Go Bold, All for One, Be a Pro) という全社員が共有する行動指針のもと行動しています。

▼ Engineering 組織が目指すもの


チーム一丸となり、Go Boldにオーナーシップを発揮して個が成長し、メルカリのミッションの実現に向けた挑戦をし続けていきます。

▼Job Description

As a Machine Learning Engineer at Mercari, you will apply your machine learning skills to develop the Mercari C2C (consumer to consumer), marketplace app. Advancements in machine learning and computational resources are leading to remarkable innovations in both technology and business. We are actively utilizing advanced machine learning technologies in order to provide a more convenient and fun marketplace.

Using sales and transaction data, engineers in this position will utilize machine learning technology to handle a diverse set of tasks such as optimizing search features, image recognition, anomaly detection, and recommendations. They will also work together with our server-side engineers and data scientists to design algorithms and conduct implementation work on our services.

In addition, Merpay members will use machine learning to work on tasks involving credit scoring, fraud detection, and recommendation engines. Members will be asked to work together with product managers to conduct a complete range of duties, including identifying business challenges, conducting mathematical modeling, implementation and feedback, and microservice development and operation.

▼ About Mercari & Merpay ML Teams

Mercari’s Machine Learning Team consists of members coming from very diverse backgrounds, featuring an environment buzzing with English conversations.

The development environment generally involves the use of cloud services and allows for unlimited use of computing resources such as GPUs within a realistic range. Members will have the opportunity to conduct machine learning modeling utilizing data from the large-scale Mercari products. They will develop services that users directly interact with, and work in an environment where they can receive direct feedback, allowing them to make discoveries about machine learning that cannot be found through research.

Credit scoring models using machine learning are the core technology of some of Merpay’s services such as Merpay deferred payment. There are also chances to work with cutting-edge model-driven financial services utilizing machine learning. Even while pursuing this technology, we value the selection process when choosing which kinds of technology best match for our business challenges. In addition to GCP, there will be opportunities to work with engineering fields like microservice creation, online/offline experimental design and performance evaluation, and constructing models that can withstand the service.

▼Technical Environment


機械学習技術を活用して、フリマアプリ「メルカリ」の機能・サービス開発を行っていただきます。 機械学習技術の向上や計算機資源の充実に伴い、機械学習技術を応用した技術・サービスも近年著しく発展しています。 高度な機械学習技術を積極的に取り入れて、より便利で楽しいマーケットプレイスを提供します。

本ポジションのエンジニアは、お客様に便利に安全に売買を楽しんでいただくために、購買データや取引データをもとに、機械学習の技術を用いて、検索最適化、画像認識、行動予測、異常検知、レコメンドなど多岐にわたる課題に取り組んでいただきます。 弊社のサーバサイドエンジニアやデータサイエンティストと連携しながら、アルゴリズム設計からサービスへの実装まで携わっていただきます。


▼メルカリ/メルペイ Machine Learningについて

メルカリMachine Learning チームには様々なバックグラウンドを持った社員が集まっており、英語での会話が飛び交うようなグローバルな環境となっています。

開発環境としては、基本的にクラウドサービスを使っているので、GPUなどの計算資源も現実的な範囲で自由に活用できるようにしています。メルカリという大規模なプロダクトのデータを活用したMachine Learningのモデリングができ、実際にお客さまに活用して頂けるサービスを開発し、ダイレクトにフィードバックが頂ける環境となっており、研究では得られない実サービスへのMachine Learning活用方法の知見を得る事が出来ます。

メルペイでは、メルペイあと払いなどの新サービスは、Machine learningを活用した信用スコアリングモデルがコア技術となっており、Machine learningをベースとしたモデルドリブンな新しい金融サービス開発の最先端に触れることができます。使用する技術については最先端を追いつつも、ビジネス課題とマッチした技術選定をすることを重視しています。実サービスに耐えうるモデル構築、オフライン / オンラインの実験計画・性能評価、マイクロサービス構築に向けた、GCP上でのエンジニアリングにも携わることができます。



▼ Minimum Requirements


▼ Our Ideal Candidate

・A skilled communicator capable of offering valuable insight in team discussions

・Capable of taking on bold challenges and learning from mistakes

・Proactive and capable of thinking independently for the good of the team

・Eager to gain new knowledge and ready to proactively challenge themselves using the newest technologies

▼ Language Ability

・Business level English or Japanese



▼ 求める人物像

▼ 言語能力



▼Contract Type




▼Work Hours


 Able to work more than 20 hours per week


・Hourly wage (Salary: Negotiable)











・Full transportation coverage

・Custom PC

・Dual screen if needed

・Visa support

・Accommodation for those who are from outside of Tokyo area






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