Jobs in Japan
Explore hand-picked jobs in Japan for English speakers across tech, education, marketing, and more.
Vetted companies only. Apply from overseas.
Explore hand-picked jobs in Japan for English speakers across tech, education, marketing, and more.
Vetted companies only. Apply from overseas.
MercariFor more details, see the Overview of Our Positions section on our Careers site. The AI Platform team drives Mercari Group's transformation into an "AI-Native company" from the perspective of technical foundations. We design, develop, and operate shared AI infrastructure used across the company, including an LLM Gateway, MCP Gateway, and Agent Sandbox, and we also build the AI Agents that work alongside development and operations on the ground. What we build is used in two ways. First, as services that every role—including engineers, designers, and PMs—uses directly in their daily work. Second, as shared building blocks that other engineering teams inside Mercari use to construct AI workflows tailored to their own domains. For the former, we create an environment where every role can demonstrate AI as a baseline skill, through developing AI Agents and running PoCs for AI SaaS. For the latter, we provide foundations with enough generality for other teams to extend on their own, and enough reliability for them to trust with real work. In this role, you will work as an enabler for AI-native development across Mercari Group while owning the shared AI platform it runs on: you build the mechanisms that let other teams work AI-natively, and you operate the production services those mechanisms depend on.
- Empathy with Mercari Group and each company's mission and values - Experience designing, developing, and operating backend or platform/infrastructure systems for large-scale web services - Production experience building applications with one of Go, TypeScript, Python, etc. - Experience developing/operating managed services or SDKs for internal developers and improving developer productivity - Experience designing and operating infrastructure on cloud platforms such as Google Cloud Platform (including Kubernetes, Terraform, etc.) - Experience designing and implementing applications or platforms using Generative AI / LLMs - Strong communication skills to collaborate with multiple stakeholders, lead technical decision-making, and drive projects forward - Experience acting as the owner of technical quality in your area, making the case for medium- to long-term investments such as architecture, standards, and shared foundations in business terms, and driving them forward - Ability to form hypotheses and make autonomous decisions in uncertain situations and execute effectively - Someone who incorporates AI into their daily development work and reviews its output with their own judgment rather than taking it at face value
- Experience developing/operating AI platforms such as MCP Servers, AI Agents, and AI agent execution environments - Experience designing interfaces and implementing guardrails on the premise that AI Agents operate autonomously - Experience designing evaluation methodologies for AI agents/LLM applications (e.g., defining evaluation criteria, building benchmarks, quantitatively validating quality through A/B tests, etc.) - Experience improving development processes / harness engineering using AI development tools (Claude Code, Codex, Cursor, etc.) - Hands-on experience in Developer Productivity / Platform Engineering / SRE - OSS contributions and community activity experience
