Product Engineer, Ad Tech, Machine Learning - Mercari

Posted 6/1/2026 · last confirmed live 8/26/2026

本ポジションは日本語JDの用意がありません。 Product Engineer, Ad Tech, Machine Learning – Mercari Employment Status:　Full-time Work Hours: Full Flextime (no core time) Office: Roppongi 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. Passion For The Product Grow Together Solve Through Mechanisms Collaborate Openly For more details, please see the following link: Engineering Culture 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. In the Ads Optimization Team… Mercari Ads offers various advertising solutions such as those for C2C sellers, Shops sellers, and external advertisers. The Ads Optimization Team is responsible for the overall optimization logic to achieve campaign goals for advertisements handled by Mercari Ads. The team improves advertising effectiveness using technologies such as search, recommendations, and machine learning. See here for more information about our mission and values. Work Responsibilities Lead optimization areas in the Ad-Tech domain. Utilize data science and machine learning technologies to identify business challenges, develop and implement models, and continuously improve productivity and reliability through iterative enhancements. Focus on mid to long-term business goals and impact, propose key issues to be resolved, and prioritize them effectively. Employ a data-driven approach to formulate hypotheses, design evaluation strategies, and develop appropriate machine learning models. Specific Responsibilities Propose, promote, implement, and validate business improvement plans. Develop and maintain machine learning models in the advertising domain, including recommendation systems, matching optimization, and ad classification. Apply statistical and data science techniques to uncover product insights and drive optimization based on business logic. Enhance the performance of advanced machine learning models by leveraging embeddings for images and text. Design time-series models to evaluate advertising effectiveness and optimize advertising budget strategies. Unique Challenges Develop advertising solutions for media with over 20 million MAUs Mercari's advertising solutions are still in the early stages, but they are expected to make a significant impact on Japan's advertising market. Challenge revolutionary advertising initiatives beyond traditional frameworks By utilizing extensive product, fintech, and user behavior data, it is possible to tackle predictive modeling challenges and create business impact. Focus on not only accuracy but also business impact and user experience (UX) during model development. Participate in creating high-quality products with machine learning as a core competency. Lead the entire lifecycle of machine learning products, from planning and proposing to development and deployment. Qualifications Required Experience/Skills Someone who can align with the mission and values of the Mercari Group and its companies. Experience in leading the optimization domain in Ad-Tech and creating significant business impact. Basic knowledge of the digital marketing domain. Experience in constructing the entire process from planning and designing data analysis to performing analysis and delivering actual outputs. Programming skills in SQL, Python, and Go. A deep understanding of the fundamentals of machine learning and software engineering. Experience building models using machine learning libraries such as scikit-learn and LightGBM. Basic to intermediate knowledge of statistics and data science. Preferred Experience/Skills Experience in developing microservices using k8s. Experience in building and operating large-scale ETL or ELT pipelines. Experience in developing and operating recommendation models for advertisements. Experience in large-scale search systems. Language Language Requirements (one of the following): English: Proficient (CEFR - C1) Japanese: Independent (CEFR - B2) preferred For details about CEFR, see here . Learn More About Mercari Group Careers site: https://careers.mercari.com/en/ Mercan: https://mercan.mercari.com/en/ Social media: X / Linkedin 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 Application screening Skill assessment: For engineering positions, you will be asked to complete a skill assessment on HackerRank or GitHub. For non-engineering positions, you may be asked to complete an assessment depending on the position. (The timing of the assessment may coincide with the interview process.) Interview: The number of interviews may vary depending on the position. Reference check: We will ask for online references around the timing of the final interview. Offer: Offers will be determined carefully in consideration of the final interview and the reference check. 　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.

This role is published by Mercari, inc. on workable. SwiftFit is not the employer and does not accept applications.