TECH-ENG-32. Senior Fullstack Engineer（Mico Message）_TokyoDev

TECH-ENG-32. Senior Fullstack Engineer（Mico Message）_TokyoDev 仕事概要 ## Job Overview ### About the Role **Mico Message** is Mico’s AI-native customer engagement platform. Through messaging automation, real-time communication, and AI-powered interactions, we develop systems that build meaningful relationships between businesses and their customers. As a **Full Stack Lead Engineer**, you will lead the design and development of both frontend and backend systems powering Mico Message. Beyond implementation, you will provide technical leadership across architecture design, engineering best practices, mentoring, and operational excellence. Working closely with our Product, Design, AI, and Infrastructure teams, you will help deliver scalable and intuitive customer engagement experiences used by enterprise customers in Japan and across global markets. --- ## Responsibilities * Lead the design and development of scalable frontend and backend systems for Mico Message * Build and enhance customer-facing applications as well as internal operational tools * Design robust APIs, backend services, and platform integrations * Drive technical decision-making and contribute to system architecture discussions * Collaborate closely with Product and Design teams to shape product direction and user experience * Continuously improve system reliability, scalability, performance, and operational observability * Develop well-tested, maintainable code following modern engineering best practices * Establish and improve engineering standards, development workflows, and technical processes * Mentor engineers through code reviews, technical guidance, and knowledge sharing * Troubleshoot and resolve complex production issues in distributed systems * Communicate effectively across cross-functional teams in both Japanese and English * Take end-to-end ownership from requirements gathering through production deployment and ongoing operation --- ## Organization **Emerging Product Engineering Division** **Mico Message Engineering Team** --- ## What We Expect We are looking for someone who can: * Enjoy solving complex technical and product challenges while balancing speed and long-term maintainability * Communicate effectively with both technical and non-technical stakeholders * Work independently while collaborating in a distributed, remote-first environment * Take meaningful ownership of system architecture and product direction * Contribute proactively to engineering culture and technical standards --- ## What You'll Gain * The opportunity to shape the future of AI-powered customer engagement * Significant influence over architecture, engineering standards, and product direction * High ownership and autonomy in decision-making * A collaborative, global, remote-first engineering culture * Continuous learning and professional growth opportunities * Competitive compensation and benefits * Flexible working arrangements built on trust and accountability --- ## Career Opportunities * Advance your expertise as an Engineering Lead toward roles such as Software Architect or Technical Lead * Grow into Engineering Manager or CTO-track positions through involvement in both product and business strategy * Play a key role within a global engineering organization --- # About Mico At Mico, our mission is to create a richer society by building **Lifetime Trust** between brands and consumers through meaningful conversations. Our long-term vision is to become **Asia's No.1 Brand Empowerment Company**, delivering the most trusted customer engagement platform across Asia. Achieving this vision requires solving ambitious technical and business challenges—and we're looking for exceptional people who are excited to tackle them. At Mico, every team member is empowered to take initiative and make a meaningful impact. --- ## Mission **To empower every brand by building lifetime trust through humanlike technology.** We believe every brand deserves the opportunity to create meaningful moments with its customers. Through AI-powered, humanlike technology, Mico helps brands build lasting relationships that drive sustainable business growth. --- ## Vision **Asia No.1 Brand Empowerment Company** We believe every brand has unlimited potential. Our purpose is to empower every brand by helping businesses build sustainable trust with their customers—not simply through marketing campaigns, but through meaningful, human-centered communication. With intuitive UI/UX and humanlike AI technology, we create engaging customer experiences that unlock the true value of every brand. --- # Our Products ## Mico Engage AI Japan's leading customer engagement platform with one of the country's largest messaging integration ecosystems. The platform provides an end-to-end solution covering: * Customer acquisition from websites * Personalized messaging powered by customer data * One-to-one customer communication * Integration with external systems Helping businesses grow from customer acquisition to long-term loyalty. --- ## Mico Voice AI An AI voice platform that automates outbound customer calls using highly natural, humanlike speech. Beyond automation, it creates memorable customer interactions while improving both operational efficiency and customer engagement. --- ## BizClo A solution that enables enterprise companies to fully leverage LINE as a strategic business communication channel. BizClo removes the limitations of one-to-one LINE chat, enabling organizations to build scalable and sustainable customer relationships. --- ## Micomii A LINE-based membership platform for retail stores and restaurants. Features including digital membership cards, loyalty programs, stamp rallies, and rewards help businesses increase repeat customers without relying on third-party marketplace platforms. --- # Why Mico AI? ## Massive, High-Quality Data Mico leverages vast amounts of customer interaction data—including clicks, browsing behavior, and engagement history—to power highly accurate AI decision-making around: * Who to engage * What content to deliver * When to deliver it Our competitive advantage comes from both the quality and scale of our proprietary data. --- ## Proprietary Data Infrastructure Unlike many AI companies, we build and manage our own datasets. This enables faster iteration, greater flexibility, and continuous AI improvement without relying on third-party data providers. --- ## World-Class AI Team Our AI organization includes talented engineers from Japan, India, the Philippines, Taiwan, and many other countries. Together, they continuously improve the accuracy and capabilities of our AI technologies. --- # Why Join Mico? ## High-Growth Market × High-Growth Company * Serving the rapidly expanding Commerce SaaS market, expected to exceed ¥30 trillion globally * 1,100% business growth over the past four years * ¥6.3 billion in total funding (including ¥3.5 billion Series B) * Market leader in LINE marketing solutions in Japan --- ## Customer-First Culture Our mission is to empower every business. We live by the principle: **WOW THE CUSTOMER** We obsess over solving real customer problems and delivering measurable results. --- ## Great People * Open and transparent communication * Strong "All for One" teamwork * A giving mindset * A global organization representing more than 20 nationalities --- ## Work Environment ### Flexible Working Style * Hybrid work * Flexible working hours * Six paid Life & Health leave days annually ### Learning & Growth * Up to ¥55,000 annual reimbursement for books and professional development * Leadership development programs * Structured career growth opportunities ### Transparency * Company-wide TGIM meetings * Quarterly business updates from leadership ### Fair Evaluation * OKR-based semiannual performance reviews * Continuous feedback culture --- 必須スキル ## Job Overview ### About the Role **Mico Message** is Mico’s AI-native customer engagement platform. Through messaging automation, real-time communication, and AI-powered interactions, we develop systems that build meaningful relationships between businesses and their customers. As a **Full Stack Lead Engineer**, you will lead the design and development of both frontend and backend systems powering Mico Message. Beyond implementation, you will provide technical leadership across architecture design, engineering best practices, mentoring, and operational excellence. Working closely with our Product, Design, AI, and Infrastructure teams, you will help deliver scalable and intuitive customer engagement experiences used by enterprise customers in Japan and across global markets. --- ## Responsibilities * Lead the design and development of scalable frontend and backend systems for Mico Message * Build and enhance customer-facing applications as well as internal operational tools * Design robust APIs, backend services, and platform integrations * Drive technical decision-making and contribute to system architecture discussions * Collaborate closely with Product and Design teams to shape product direction and user experience * Continuously improve system reliability, scalability, performance, and operational observability * Develop well-tested, maintainable code following modern engineering best practices * Establish and improve engineering standards, development workflows, and technical processes * Mentor engineers through code reviews, technical guidance, and knowledge sharing * Troubleshoot and resolve complex production issues in distributed systems * Communicate effectively across cross-functional teams in both Japanese and English * Take end-to-end ownership from requirements gathering through production deployment and ongoing operation --- ## Organization **Emerging Product Engineering Division** **Mico Message Engineering Team** --- ## What We Expect We are looking for someone who can: * Enjoy solving complex technical and product challenges while balancing speed and long-term maintainability * Communicate effectively with both technical and non-technical stakeholders * Work independently while collaborating in a distributed, remote-first environment * Take meaningful ownership of system architecture and product direction * Contribute proactively to engineering culture and technical standards --- ## What You'll Gain * The opportunity to shape the future of AI-powered customer engagement * Significant influence over architecture, engineering standards, and product direction * High ownership and autonomy in decision-making * A collaborative, global, remote-first engineering culture * Continuous learning and professional growth opportunities * Competitive compensation and benefits * Flexible working arrangements built on trust and accountability --- ## Career Opportunities * Advance your expertise as an Engineering Lead toward roles such as Software Architect or Technical Lead * Grow into Engineering Manager or CTO-track positions through involvement in both product and business strategy * Play a key role within a global engineering organization --- # About Mico At Mico, our mission is to create a richer society by building **Lifetime Trust** between brands and consumers through meaningful conversations. Our long-term vision is to become **Asia's No.1 Brand Empowerment Company**, delivering the most trusted customer engagement platform across Asia. Achieving this vision requires solving ambitious technical and business challenges—and we're looking for exceptional people who are excited to tackle them. At Mico, every team member is empowered to take initiative and make a meaningful impact. --- ## Mission **To empower every brand by building lifetime trust through humanlike technology.** We believe every brand deserves the opportunity to create meaningful moments with its customers. Through AI-powered, humanlike technology, Mico helps brands build lasting relationships that drive sustainable business growth. --- ## Vision **Asia No.1 Brand Empowerment Company** We believe every brand has unlimited potential. Our purpose is to empower every brand by helping businesses build sustainable trust with their customers—not simply through marketing campaigns, but through meaningful, human-centered communication. With intuitive UI/UX and humanlike AI technology, we create engaging customer experiences that unlock the true value of every brand. --- # Our Products ## Mico Engage AI Japan's leading customer engagement platform with one of the country's largest messaging integration ecosystems. The platform provides an end-to-end solution covering: * Customer acquisition from websites * Personalized messaging powered by customer data * One-to-one customer communication * Integration with external systems Helping businesses grow from customer acquisition to long-term loyalty. --- ## Mico Voice AI An AI voice platform that automates outbound customer calls using highly natural, humanlike speech. Beyond automation, it creates memorable customer interactions while improving both operational efficiency and customer engagement. --- ## BizClo A solution that enables enterprise companies to fully leverage LINE as a strategic business communication channel. BizClo removes the limitations of one-to-one LINE chat, enabling organizations to build scalable and sustainable customer relationships. --- ## Micomii A LINE-based membership platform for retail stores and restaurants. Features including digital membership cards, loyalty programs, stamp rallies, and rewards help businesses increase repeat customers without relying on third-party marketplace platforms. --- # Why Mico AI? ## Massive, High-Quality Data Mico leverages vast amounts of customer interaction data—including clicks, browsing behavior, and engagement history—to power highly accurate AI decision-making around: * Who to engage * What content to deliver * When to deliver it Our competitive advantage comes from both the quality and scale of our proprietary data. --- ## Proprietary Data Infrastructure Unlike many AI companies, we build and manage our own datasets. This enables faster iteration, greater flexibility, and continuous AI improvement without relying on third-party data providers. --- ## World-Class AI Team Our AI organization includes talented engineers from Japan, India, the Philippines, Taiwan, and many other countries. Together, they continuously improve the accuracy and capabilities of our AI technologies. --- # Why Join Mico? ## High-Growth Market × High-Growth Company * Serving the rapidly expanding Commerce SaaS market, expected to exceed ¥30 trillion globally * 1,100% business growth over the past four years * ¥6.3 billion in total funding (including ¥3.5 billion Series B) * Market leader in LINE marketing solutions in Japan --- ## Customer-First Culture Our mission is to empower every business. We live by the principle: **WOW THE CUSTOMER** We obsess over solving real customer problems and delivering measurable results. --- ## Great People * Open and transparent communication * Strong "All for One" teamwork * A giving mindset * A global organization representing more than 20 nationalities --- ## Work Environment ### Flexible Working Style * Hybrid work * Flexible working hours * Six paid Life & Health leave days annually ### Learning & Growth * Up to ¥55,000 annual reimbursement for books and professional development * Leadership development programs * Structured career growth opportunities ### Transparency * Company-wide TGIM meetings * Quarterly business updates from leadership ### Fair Evaluation * OKR-based semiannual performance reviews * Continuous feedback culture --- 歓迎スキル * Experience with statically typed languages, including TypeScript or Python type hints * Experience using gRPC and Protocol Buffers * Experience with Elixir/Phoenix or functional programming * Experience building scalable SaaS platforms * Understanding of conversational AI and LLM-powered applications * Experience designing event-driven architectures and distributed systems * Experience collaborating closely with Infrastructure or DevOps teams * Experience improving engineering processes and development workflows * Experience working in fast-growing startups * Interest in AI-assisted software development workflows 求める人物像 * Enjoys solving complex technical and product challenges * Balances speed with long-term maintainability * Communicates effectively with both technical and non-technical stakeholders * Thrives in collaborative, distributed environments while working independently * Takes strong ownership of systems and product direction * Is passionate about shaping engineering culture and raising technical standards 応募概要 給与 **Annual Salary** **JPY 7,000,000 – 9,000,000** Compensation will be determined based on your previous salary, experience, and skills. **Salary Breakdown** * Monthly salary: **JPY 585,000 – 750,000** * Base salary: **JPY 432,832 – 554,913** * Fixed overtime allowance (45 hours/month): **JPY 152,168 – 195,087** * Any overtime exceeding 45 hours will be paid separately. * Annual salary system, paid in **12 monthly installments** * Commuting allowance provided in accordance with company policy 勤務地 You may choose to work from either our **Tokyo** or **Osaka** office, depending on your preference. We offer a **hybrid work model**, combining remote work with office attendance. Employees are encouraged to work from the office **at least once per week**. ### Osaka Office JAM BASE 5F (JAM-OFFICE 5-A & 5-B) Grand Green Osaka North Building 6-38 Ofukacho, Kita-ku, Osaka, Japan ### Tokyo Office WeWork The ARGYLE Aoyama 6F 2-14-4 Kita-Aoyama, Minato-ku, Tokyo, Japan 雇用形態 Full-time 勤務体系 * Standard working hours: **9:00 AM – 6:00 PM** (Includes a 1-hour lunch break) * Flexible working hours with **core hours from 10:00 AM to 4:00 PM** * Employees above a certain grade may be eligible for a discretionary work system in accordance with company policy. 試用期間 3 months (in principle) * No changes to compensation or benefits during the probation period 福利厚生 * Transportation allowance (bicycle commuting permitted) * Company-provided laptop * Company mobile phone (for eligible positions) * Flexible work start time selection (can be requested every two months) * Comprehensive social insurance * Health insurance * Employees' pension * Employment insurance * Workers' compensation insurance * Life & Health leave * Annual health checkups * Parental and childcare support programs * Employee club activities