Mercari, inc. · Minato City, Japan (Hybrid) · Full-time · Posted 2026-06-30
Workplace: hybrid
Department: Engineering
JD in English follows. 和文の後に英文JDをご覧いただけます。
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メルカリグループについて
あらゆる価値を循環させ、あらゆる人の可能性を広げる
「地球資源が限られているなか、より豊かな社会をつくるために何ができるか」。2013年、創業者の山田進太郎が世界一周の旅で抱いた課題意識から、フリマアプリ「メルカリ」は生まれました。私たちは、物理的なモノやお金に限らずあらゆる価値を循環させることで、誰もがやりたいことを実現し、人や社会に貢献するための選択肢を増やすことができると信じています。テクノロジーの力で世界中の人々をつなぎ、あらゆる人の可能性が発揮される世界を実現していきます。メルカリグループの目指すべき方針についてはMercari Culture Docをご覧ください。
組織・チームのミッション
Mercari Engineering Principles
Mercari Engineering Principlesは、メルカリのエンジニアリング組織における信念や行動の基盤となる共通認識を明文化したもので、メルカリのメンバー全員が共有するMission、Value、Cultureをエンジニアリングの視点から補完するものとなります。
これらのPrinciplesは、私たちが長期的に実現しようとする理想的な姿を定義することで、最終的にメルカリのミッションを達成するために活用していきます。
詳細についてはエンジニアリングカルチャー をご覧ください
メルカリのロジスティクスチームは、メルカリのシステム全体での配送プラットフォームとサービスの提供を担当しています。私たちのビジョンは、国内・海外配送の両方にメルカリのシステムを導入しやすくするため、物流システムをシンプルにすることです。現在、お客さまに安心してご利用いただける配送体験を提供するため、複数の配送パートナーと連携しています。これらすべてのパートナーとその業務を管理することは、簡単なことではありません。一方で、新規事業の開発や、お客さま向けの魅力的な新サービスの提供にも取り組んでいます。配送サービスプラットフォームとして、新規事業の拡大を支援し、競争力のある価格で最高の体験を提供することが私たちの使命です。
メルカリのミッション・バリューについての詳細はこちらをご覧ください
業務内容
ユニークなチャレンジ
日本最大のC2Cマーケットプレイスである「メルカリ」は、お客さまに優れたサービスを提供することを目指しています。配送は、社外パートナーに依存し、そのシステムとも連携が不可欠な重要なシステムの一つです。私たちは常に、革新的な機能を通じてビジネスを拡大する方法を探しています。そのためには、追加の機能開発や他サービスからの負荷にも対応できるバックエンドシステムの構築が欠かせません。ステークホルダーやパートナーの期待値をコントロールしながら、メルカリのシステムが制約やボトルネックになることを防ぐという点が、この仕事特有の難しさだと思います。
さらに、配送会社との提携を増やしてビジネスのグローバル展開を行っています。そのため、バックエンドシステムには、社外・グローバルパートナーとの連携に対応できる柔軟性が求められます。パートナー側のシステムも、変化するビジネスニーズに合わせて進化し続けているため、私たちもその変化に柔軟に対応できるシステムづくりを進めなければなりません。
応募要件
求める経験・スキル
4年以上の大規模バックエンドシステムの開発経験
変化の激しい、AI駆動の環境で快適に活躍できる方
歓迎する経験・スキル
Goを用いたAPIの設計・開発・運用経験
サードパーティと連携した開発経験
語学力
日本語:Proficient (CEFR – C1) 必須
CEFRの詳細については、こちらをご覧ください
メルカリグループについて知る
メルカリグループではメルカリグループおよび各カンパニーのミッションとバリューへの共感・体現を大切にしています。メンバーが発揮する価値の総量が最大化されるような組織づくりを推進するために、候補者のみなさんの経験やスキルをより正しく理解したいと考えています。
選考の流れ
選考における機会の平等
メルカリでは、バックグラウンドによって個人の可能性が決めつけられることなく、自由に価値を生みだす機会を手にできる社会の実現を目指しています。そしてメルカリがミッションを実現するために「Inclusion & Diversity」という考え方は不可欠な存在だと考えています。
これはもちろん、私たちの採用方針にもあてはまります。採用活動においても、メルカリのミッション・バリューに共感する、様々なバックグラウンドの方にジョインしていただけるよう、年齢、性別、性的指向、人種、宗教、身体能力、その他記号に基づくあらゆる差別をなくすことを約束します。詳しくは、I&D Statementをご覧ください。
なお、ご応募の際にはプライバシーポリシーをご確認ください。
For more details, see the Overview of Our Positions section on our Careers site.
About Mercari
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
Organization/Team Mission
Mercari Engineering Principles
Mercari Engineering Principles are a shared understanding that serves as the foundation of engineering beliefs and behavior at Mercari. The Engineering Principles are designed to complement the organizational identity (Mercari’s mission, values, and culture) from an engineering viewpoint.
These principles ultimately help us achieve Mercari’s mission by defining the ideal state we seek to realize in the long term.
For more details, please see the following link:
We operate with an AI-native development approach, pursuing both speed and maximum customer value at the same time.
Engineers in this position are expected to act as Product Engineers (PdE), holding end-to-end responsibility from initial specification to successful delivery. You will be required to proactively dive in from the definition phase and autonomously lead everything from sharpening product specs and building consensus, to ensuring quality/measurement and making the final release.
Logistics team is responsible for providing shipping platforms and services across Mercari systems. Our vision is to simplify the logistics system in order to onboard Mercari systems for both local and global shipping. We are currently working with multiple shipping partners in order to provide reliable shipping experience for our users. Managing all these partners and their operations is challenging. In the mean time we are in the process of developing new businesses and providing exciting new services to our users and as a shipping service platform it's our mission to help expand the new businesses and provide the best experience with competitive pricing.
See here for more information about our mission and values.
Work Responsibilities
Unique Challenges
Mercari is a leading C2C marketplace in Japan and aims to provide excellent services to our customers. Shipping is one crucial system which relies on external partners and has dependencies on their systems. And we are always looking for ways to expand our business by providing innovative features. In order to do that we also need to make sure our backend systems are capable of managing additional feature development and load from other services. This is a unique challenge for us to manage the expectations of our stakeholders and partners and make sure our systems don’t have limitations or become bottlenecks.
Additionally we are expanding our business globally and by having more partnerships with shipping companies. Which means that backend systems should be able to integrate with external and global partners. Partner systems as well keep evolving and changing to accommodate changing business needs which means we also need to develop our systems in a way which can accommodate such changes coming from partners.
Qualifications
Required Experience/Skills
Have 4+ years of experience working on large-scale backend systems.
Comfortable thriving in a fast-paced, AI-driven environment with constant change.
Preferred Experience/Skills
Experience designing, developing and operating APIs in Go programming language.
Experience in integrating development with third parties.
Language
Japanese: Proficient (CEFR - C1) required
For details about CEFR, see here.
Learn More About Mercari Group
Recruiting at Mercari
At Mercari Group, we value empathizing with and embodying the mission and values of the Group and each company. To promote the creation of an organization that maximizes the total amount of value exhibited by all members, we would like to understand the experience and skills of each candidate as accurately as possible.
Recruiting cycle at Mercari Group
Learn more about our recruiting process here.
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 Inclusion & Diversity 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 I&D statement.
Please read and acknowledge our Privacy Policy prior to submitting your application.
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Mercari runs a mobile peer-to-peer marketplace that lets people buy and sell secondhand goods across categories like fashion and electronics. Sellers list items by taking photos in the app, buyers browse and complete purchases, with payments held in escrow and integrated shipping options to secure transactions. It earns revenue from selling fees in different regions (about 10%), plus services like Merpay and promoted listings, and differentiates itself with a simple mobile experience, buyer protection, escrow, and business-enabled Mercari Shops. Its goal is to promote sustainable consumption by extending the life of goods and supporting a circular economy through a large global community.
Company Size
1,001-5,000
Company Stage
IPO
Headquarters
Tokyo, Japan
Founded
2013
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Mercari offers free holiday shipping on $50+ orders, brings back Fashion Exchange. Published: Oct 19 2026 Updated: Oct 19 2026 Mercari is offering free shipping on qualifying orders of $50 or more this holiday season, bringing back its Fashion Exchange program and introducing additional shipping protection options for sellers. The company announced the upcoming changes in emails to buyers and sellers October 17, just two days before previously announced shipping rate increases take effect across USPS, UPS and FedEx. The free shipping promotion runs from October 22 through January 4, 2027, covering eligible individual items and bundled purchases from the same seller. Under the terms, single-item purchases must use Mercari's Best Rate prepaid shipping option, while bundles qualify regardless of shipping rate or carrier. Both are limited to orders of $50 or more weighing no more than 5 lbs, with additional size restrictions for individual shipments. The promotion is the latest in a series of temporary shipping incentives Mercari has used to stimulate US sales, including free First Class Envelope shipping for some trading cards and an extension of its discounted 49¢ envelope rate through January 4. Mercari had also teased another holiday shipping promotion when announcing its October 19 rate increases, but had not previously disclosed the details. Unlike those earlier offers targeting lower-priced collectibles, the new promotion encourages larger purchases and bundles, both priorities management discussed in its latest earnings report. Mercari US reported 15% year-over-year GMV growth in fiscal Q4 2026, with Monthly Active Users increasing 4% to 4.2 million. The company has credited shipping discounts and strength in Entertainment & Hobbies with helping drive its recent growth. Mercari is targeting at least 10% US GMV growth in fiscal 2027 while maintaining roughly break-even profitability, with increasing average purchase amounts among management's priorities. During the August earnings Q&A, executives specifically discussed bundles as a way to spread shipping costs across multiple lower-priced purchases. The new $50 threshold could help encourage those larger purchases and bundles, though Mercari has not disclosed how much it expects to spend on the promotion or what impact it anticipates on order volume. Mercari is also bringing back Fashion Exchange for the holidays, allowing buyers to return select clothing, shoes and bags for Mercari credit when purchases don't fit, have an unpleasant smell or otherwise don't meet expectations. Sellers will still receive their full payment and an automatic rating, with Mercari handling the exchange process and associated costs. The program was first introduced as a limited pilot in July 2025, covering select clothing items priced at $100 or less, before returning later that year with expanded eligibility for bags and shoes during the holiday shopping season. Under the previous Fashion Exchange terms, buyers had 72 hours after delivery to request an exchange, with approved items shipped back to Mercari rather than the original seller. Instead of receiving a refund to their original payment method, buyers were issued Mercari credits that expired after 30 days. A start date has not yet been announced and Mercari has not confirmed whether the previous $100 price limit and other eligibility restrictions will apply this time. The company has brought Fashion Exchange back repeatedly since its initial pilot without making it a permanent part of its return policy. Mercari also told sellers it will soon introduce Shipping Protection Plus+, an optional program offering additional protection against loss or damage in transit for higher-value merchandise. Under the marketplace's existing Shipping Protection policy, eligible shipments using Mercari prepaid labels are covered for up to $200 on standard, economy and Media Mail services, or up to $20 for First Class Envelopes, subject to packaging, shipping and claims requirements. The new option would allow sellers to add coverage beyond those existing limits, but Mercari has not yet announced a launch date, pricing, maximum coverage amounts or whether any additional eligibility restrictions will apply. Liz Morton is founder and editor of Value Added Resource. She spent 17+ years operating ecommerce businesses before launching VAR. Her reporting focuses on seller experience, marketplace strategy and corporate accountability.
Japan METI's cicrular Economy Action Week begins today. From today until 7 October, METI is running its "Circular Economy (CE) Action Week," timed to coincide with the annual 3R (Reduce, Reuse, Recycle) Promotion Month that government ministries hold every October. Rather than another top-down advocacy for recycling or policy announcement, the campaign is asking consumers to adopt a circular habit of buying, using, separating and, eventually, circulating. Ten companies are helping consumers to visualise how the habits look like in their own way. Fashion rental service airCloset is discounting its first month's subscription by up to 30%, while furniture rental platform CLAS is cutting monthly fees on its CIRCLE range by as much as half. Suntory is publishing videos and quizzes on its bottle-to-bottle horizontal recycling, and Seven-Eleven Japan is pointing customers back to its in-store PET bottle collection machines, which have now taken in a cumulative 800 million bottles, rewarding five bottles with one nanaco point. Panasonic is launching a subscription water purifier that does away with disposable bottles altogether, Bandai Spirits is showcasing its Gunpla plastic model recycling scheme, Lion is collecting used toothbrushes for reprocessing, and Kao is using social media to explain its own resource loops. Reform Studio is hosting hands-on repair and remake sessions at AEON Mall Urawa Misono from 2 to 4 October. There will also be a physical event, to be held at MARK IS Minatomirai, where a Pac-Man tie-in event on 3 and 4 October turns waste sorting into a ticket to arcade play. Mercari, meanwhile, is reaching both ends of the generational spectrum, offering a week-long social media giveaway, while their Mercari Kids Flea Market events in Tokyo on 17 October and Osaka on 25 October let children try buying and selling first-hand. In additional to the campaign, METI also unveiled a "CE Action" logo to mark its launch. Any member of its Circular Partners (CPs) network, a roughly 600-strong public-private partnership, can now use on their own materials.
How to crosslist from Mercari to Poshmark: A reseller's guide. Published 2026-09-18 If you already sell on Mercari, bringing your active catalogue over to Poshmark is one of the most effective ways to increase sales. Poshmark operates as a social commerce platform with a large buyer base for fashion and lifestyle items, while Mercari functions as a straightforward resale app. Learning how to crosslist your items between both marketplaces lets you reach two distinct audiences without spending hours retyping every listing by hand. Understanding the differences: Mercari vs Poshmark. Mercari and Poshmark attract different buyer demographics and use distinct listing structures. Mercari caters to search-driven shoppers looking for clothing, electronics, home goods, and collectibles. Poshmark leans heavily into social commerce, where community sharing, brand followings, and curated party feeds drive secondhand fashion discovery. When you crosslist items between channels, you must account for each platform's listing requirements. Poshmark relies on structured brand mapping profiles and specific sizing conventions, whereas Mercari offers a simpler listing structure. Adapting your inventory to fit each platform ensures your items rank well in search results and convert into sales. Key capabilities for crosslisting success. Manually copying titles, descriptions, prices, and photos between platforms takes significant time. Modern crosslisting workflows streamline this process by automating how inventory details transition between marketplaces. * Dynamic size mapper: Translates footwear and apparel sizes into the correct target marketplace taxonomy. * Brand mapping profiles: Aligns listing details with approved platform brand directories. * Real-time sold delisting: Detects sales across connected channels to remove sold items automatically and prevent double sales. * Single-click crossposting: Sends prepared drafts straight to your target marketplace accounts. Setting up your desktop listing environment. To run your crosslisting workflow efficiently, you need a desktop or laptop computer running Google Chrome. Listing automation relies on browser extensions to communicate with your signed-in seller accounts, which mobile web browsers cannot support. While web dashboards let you review inventory on a phone, photographing, drafting, and crosslisting items requires a desktop browser setup. Make sure you remain signed in to your marketplace seller accounts in Chrome. Swiftlisted is building dedicated integration lanes for Mercari and Poshmark on its roadmap. Once these lanes ship, you will be able to crosslist, translate categories, and synchronise sold items seamlessly across both platforms alongside currently supported channels. Best practices for managing multi-channel inventory. Maintaining an organised central stockroom is essential when selling across multiple channels. Keep track of item states - whether an item is a draft, live, or sold - so you always know where your stock is listed. During photography, always capture clear, well-lit shots of size tags and brand labels. Clear photos help automated vision tools draft titles, descriptions, and categories accurately, making your review process fast and straightforward before hitting post. Common questions. * Can I crosslist from Mercari to Poshmark on a mobile phone? - No. Crosslisting automation requires a desktop or laptop computer running Google Chrome with the extension installed. Mobile browsers do not support extension automation, though you can view your stockroom dashboard on mobile. * Do I need existing seller accounts on both marketplaces? - Yes. Swiftlisted posts directly to your existing store accounts on connected marketplaces - it does not create new marketplace accounts for you. * How does sold detection prevent double sales? - When an item sells on one connected platform, background sold detection detects the purchase, updates your central inventory record, and delists the sold item across your other channels. * What do I need to start crosslisting with Swiftlisted? - You need a desktop or laptop running Google Chrome, the Swiftlisted Chrome extension, item photos, and active seller accounts on the marketplaces you sell on. List once, sell everywhere. Swiftlisted photographs, describes and crosslists your stock across every marketplace you sell on - then delists it everywhere when it sells.
Mercari Selected for GENIAC robotics foundation model R&D project, implemented by METI and NEDO. Kicking off research on automating item inspection and listing to support the expansion of crossborder transactions. Mercari, Inc. ("Mercari") is pleased to announce that its research project "Research and Development on Leveraging AI Robots for Listing and Inspection Tasks" has been selected for the Generative AI Accelerator Challenge (GENIAC), a national initiative spearheaded by the Ministry of Economy, Trade and Industry (METI) and the New Energy and Industrial Technology Development Organization (NEDO). The aim of the national initiative is to strengthen the development capabilities and social implementation of generative AI in Japan. Mercari is in the midst of driving its transformation into an "AI-Native Company," focusing on rebuilding all of its organizations, development processes, and products around AI technologies. For this project, Mercari's R&D organization R4D will conduct research and development on physical AI to automate Mercari's inspection and listing tasks. R4D will use Mercari's inspection and shipping facility, which handles a wide variety of items, as a real-world testing environment. Researchers will work on three key initiatives: building on Vision-Language-Action (VLA) models[1] to create multimodal models that integrate touch and force sensing; developing camera-aware VLA models that can handle viewpoint changes; and building a data collection framework that captures and transfers the actual sensations of human work. Using this technology, researchers will strive to optimize logistics efficiency in Mercari's crossborder transactions. This is the second time this year that a Mercari project has been selected for GENIAC. The first project, announced in June, was titled "Development of a High-Precision Search and Recommendation Platform Model for the Secondary-Distribution Market Using Generative Retrieval Technology."[2] 1. AI model that interprets visual input captured from a camera and natural language commands given by a human to generate the actions of a robot in a physical space. 2. Mercari Selected for GENIAC - Generative AI Accelerator Challenge Led by METI and NEDO (https://about.mercari.com/en/press/news/articles/20260604_geniac/) The challenges of automating the inspection tasks supporting the expansion of crossborder transactions and of working with current physical AI models. In September 2025, Mercari launched the Mercari Global App, a worldwide app that allows buyers overseas to more easily, safely, and securely buy from Mercari users in Japan. The app is currently available in Taiwan, Hong Kong, and the US, with Mercari working to expand its reach by aiming to launch the same product to over 100 additional countries and territories over the mid to long term. One of the critical pieces of infrastructure behind this crossborder growth is Mercari's inspection and shipping facility. To facilitate safe and secure transactions, Japan-sourced items purchased by users overseas are collected at Mercari's facility, where they undergo inspection before they are shipped overseas. Because Mercari's crossborder transactions deal with items across various categories, items vary widely in shape and condition. Inspection also involves handling deformable items such as fabrics and bags, and manipulating components like buttons and zippers. These are tasks that are difficult to automate with conventional model-based robot control alone. In recent years, VLA models - which generate actions directly from vision and language input - have emerged and are expected to be useful in environments like these. However, in adopting current VLA models for use in item inspection and other such tasks, the following three major pain points arise: * The robot's behavior relies solely on visual information input through cameras, and it cannot gauge the appropriate amount of force to apply to an item based on its feel and response * If the camera angle during inference differs even slightly from the images the model was trained on, the trained robot becomes unable to perform the appropriate operations * Data collection through robot teleoperation is inefficient In this project, Mercari's inspection and shipping facility - which handles a wide variety of irregular items - will serve as a real-world testing environment for technical innovations aimed at overcoming these limitations of VLA models. The success of this project will do more than just further accelerate the rapidly expanding growth of Mercari's crossborder business. It aims to contribute to the establishment of physical AI infrastructure that can be applied to the physical tasks of various industries. About GENIAC. The Generative AI Accelerator Challenge (GENIAC) is a project spearheaded by METI and NEDO with the aim of strengthening the development capabilities and social implementation of generative AI in Japan. * GENIAC website: https://geniac.meti.go.jp/ * Selection announcement webpage (available only in Japanese): https://www.nedo.go.jp/koubo/CD3_100434.html For more details on this research, see the accompanying article on the R4D website. https://r4d.mercari.com/en/news/20260909_geniac_pjysicalai_details/ Mercari will continue to connect communities across industry, academia, and government, contributing to the development of cutting-edge technology and social implementation while pioneering the path toward undiscovered value.
Mercari launches new luxury recommerce marketplace July 14, 2026 by Tariq Ahmed Saeedi Editor's Pick