株式会社ミツモアのSenior Software Engineerの求人

ミツモアのミッション / Our Mission

「日本のGDPを増やし 明日がもっといい日になる と思える社会に」

労働生産性が先進国の中で低く、GDPも実質賃金も下がり続けている日本。
その閉塞感を打破するために、ミツモアはサービス産業の生産性向上を追求します。
まずは集客や見積もりを自動化するプラットフォーム「ミツモア」で、そして事業者のオペレーションの全てを効率化するSaaS「プロワン」で、さらに「プロワン」のインフラ環境と「ミツモア」で活躍する豊富なプロネットワークを掛け合わせた受発注DXサービス「ハッチュー」で。
サービス・プロダクトの利用者は急激に増えていますが、それでも目指す所へはまだ一合目。
途方もなく高い山だからこそ同じ想いを持ち、ユーザーやプロダクトにまっすぐに向き合える仲間と一緒にのぼりたい。
私たちと一緒に、世界基準のサービスを通じて、明日はきっといい日になると信じられる世の中を実現していきましょう。

About the position

We're looking for a Senior Software Engineer who is passionate about building reliable, scalable, and maintainable systems — from backend business logic to frontend user experiences.

You'll work primarily with TypeScript, with React / Next.js on the frontend and NestJS / Prisma on the backend. You'll collaborate closely with both engineers and non-engineers (product, design, biz/ops) to ship features that power the core of our product for some of Japan's largest enterprise customers.

Our Tech Stack

Not exhaustive, but the most important are:

• TypeScript everywhere;
• Node.js;
• NestJS / Prisma / PostgreSQL on the backend;
• React / Next.js on the frontend, React Native (Expo) on mobile; and
• AWS (EKS, S3, Lambda); and
• Redis.

Responsibilities

• Design and deliver features end-to-end across the stack (frontend, backend, architecture).
• Take ownership of technically challenging projects, such as refactoring, complex data modeling, or new platform integrations.
• Drive improvements in system reliability, performance, and maintainability.
• Mentor other engineers and champion high standards in code quality and architecture.
• Participate in support rotations to investigate bugs and incidents.

We value engineers who care deeply about technical quality, end-user experience, and long-term stability — not just shipping tickets fast.

How we use AI in development

We are bullish on AI as a development tool, and provide free usage of AI tools like Claude Code for our engineers. We have an internal AI task force responsible for policy, guidelines, oversight, and technology in order to empower our engineers to use AI safely and efficiently.

Requirements

• 7+ years of professional software engineering experience.
• Significant experience with TypeScript.
• 2+ years of hands-on work with React (or a similar modern frontend framework).
• Strong understanding of backend frameworks, database modeling (SQL/Prisma), and asynchronous app architecture.
• Proficiency collaborating across functions (product, design, operations, and stakeholders).
• Track record of delivering production systems with an emphasis on scalability, reliability, testability, and maintainability.
• Familiarity with modern development workflows: Git, PR reviews, CI/CD, and automated testing.
• Be located in, or be willing to relocate to, Japan (we will support relocation).

Nice to haves

While not specifically required, tell us if you have any of the following.

• Experience with our specific stack: NestJS, Prisma, PostgreSQL, AWS.
• Development and operation using containers (e.g. Docker).
• Cloud infrastructure experience (e.g. AWS or GCP).
• Familiarity with AI-assisted development workflows (e.g. Claude Code, Cursor).
• Experience building B2B or enterprise SaaS products.
• Conversational-level Japanese.

What makes this role compelling

• A diverse team of strong engineers. Engineers from 12+ countries bring diverse perspectives and skills.
• High-growth, real-world impact. ProOne is a vertical SaaS product developed by Meetsmore growing rapidly in Japan's service industry. Your work directly impacts how thousands of businesses operate daily.