Senior Software Engineer

Senior Software Engineer — Tokyo

Starting Salary Range: 9,000,000 ~ 15,000,000 JPY

Japanese level required: Business level

About the Team & Culture

• Global & Diverse Environment: Around 50% of our engineering team consists of international talent representing more than 20–25 countries and regions.
• Flexible Communication: We foster an inclusive, multicultural workspace where English is widely used for day-to-day team collaboration.

About the Role & Key Responsibilities

We are seeking a Senior Software Engineer / Tech Lead to drive architecture design, development, and team growth for complex enterprise systems. You will lead technical decisions from backend to cloud infrastructure, mentor engineers, and collaborate with cross-functional stakeholders.

• Architecture & Technical Leadership: Lead architecture design and technical selection for large-scale, complex systems (Backend, Frontend, Cloud/Infra) balancing trade-offs. Design cloud-native environments (AWS, GCP, Azure).
• Development & Delivery: Hands-on development of high-difficulty components. Lead agile development processes (Scrum/Kanban) ensuring quality and timeline adherence.
• Standards & Strategy: Establish development guidelines, coding standards, and test strategies across the team.
• Mentorship: Provide technical mentorship, code/design reviews, and career support to junior and mid-level engineers.
• Stakeholder Management: Drive clear, professional communication regarding technical feasibility with Product Managers, business teams, and client engineers.

Required Qualifications

• Experience: 7+ years of professional software engineering experience (or equivalent track record), with experience leading a small team (3+ engineers) as a Senior Engineer or Tech Lead.
• Technical Expertise: Deep expertise and hands-on production experience in at least two of the following:

Spring (Java or Kotlin)

Vue.js / Nuxt.js / Quasar

Go

C# .NET / ASP.NET

• Cloud & IaC: Strong knowledge and practical experience in cloud infrastructure design/building (AWS, GCP, or Azure) using IaC tools like Terraform or OpenTofu.
• Architecture: Hands-on experience designing modern architectures (Microservices, Distributed Systems, Event-Driven Architecture) and explaining design rationale. Strong CS fundamentals (OS, SDLC).
• Communication: Business-level English for technical communication (Reading & Writing required; Speaking preferred).

Preferred Qualifications

• Experience in Financial Systems or FinTech domains.
• Hands-on experience in Enterprise-scale system development.
• Consulting-level upstream experience (understanding client challenges and proposing technical solutions).
• Knowledge of high-standard security principles in financial systems.
• Experience in early-stage product development (PoC, MVP).
• Track record of implementing Agile frameworks (Scrum, Kanban) into engineering teams.