Senior Software Engineer (K P)

 

Senior Software Engineer Company: LiNKX Inc.

About LiNKX

Engineering-First Culture

Over 80% of our employees are engineers, and our leadership team has a strong technical background. We believe technical excellence drives business success and actively invest in continuous learning (study sessions, knowledge sharing, etc.). Our HR systems and working styles are designed with engineers’ voices at the center, including certification support and company-sponsored participation in external events.

Global & Diverse Team

Talented engineers from over 25 countries work together in a high-performance, diverse environment. Project teams typically consist of 5–8 members, usually including at least one senior engineer.

Business Domains

FinTech: Supporting modernization of core financial systems, next-generation payment platforms, and core banking systems. PharmaTech: Developing in-house SaaS solutions such as Lab Hub, which improves R&D productivity.

Position Overview

Due to rapid growth in our FinTech business driven by Japan’s financial DX initiatives, we are expanding our engineering teams. We are looking for a Senior Software Engineer who can lead the modernization of financial systems using cloud-native architectures, mobile technologies, and Generative AI (GenAI).

Unlike the traditional image of conservative financial system development, LiNKX works with forward- thinking clients and takes a PoC-driven approach, supporting projects from upstream phases such as requirement definition and solution design.

Key Responsibilities / Mission

Act as a technical decision-maker, leading architecture design and key technology selections to maximize system quality and development productivity. Drive modernization of next-generation technical platforms, particularly for financial systems, reducing technical debt and building scalable foundations.

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Mentor and technically guide mid-level engineers, serving as a core pillar of the team and elevating overall engineering capability. Lead development projects by understanding existing systems and requirements, delivering high- quality systems on time. Proactively identify and solve complex technical challenges (e.g., large-scale performance issues, security risks) to mitigate business risk. Improve team performance in measurable ways through technical guidance and code reviews (e.g., increasing autonomy of mid-level engineers).

Responsibilities

Architecture Design & Technology Selection

Lead the design of large-scale, complex systems across backend, frontend, and infrastructure, making final decisions with a clear understanding of trade-offs. Design and build cloud-native infrastructures based on AWS, GCP, or Azure.

Development Leadership

Contribute hands-on by taking ownership of high-difficulty development tasks. Apply deep knowledge of agile development processes (Scrum, Kanban) and take responsibility for project schedules and quality. Develop and manage high-quality systems, databases, and applications.

Establishing Technical Standards

Define and maintain development guidelines, coding standards, and test strategies, ensuring adoption across the team.

Mentoring & Coaching

Provide OJT, technical reviews (code and design), and career development support for junior and mid-level engineers.

Stakeholder Communication

Collaborate closely with Product Managers, business teams, and client engineers. Communicate technical feasibility, constraints, and trade-offs clearly and professionally.

Technical Environment

Languages: Java, Kotlin, JavaScript, TypeScript, Go, C#, etc. Frameworks: Spring, Vue.js, Nuxt.js, .NET Framework, etc. Infrastructure: Cloud-native environments using AWS, GCP, or Azure.

Career paths include Engineering Manager, Tech Lead, or Specialist roles.

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Development Process

While waterfall development is still common in Japan’s financial industry, LiNKX actively adopts agile methodologies. Many projects start with undefined requirements, and engineers collaborate closely with clients from the earliest phases—covering specification, design, implementation, testing, and deployment—through to user delivery.

Required Qualifications

Experience

7+ years of professional experience as a software engineer, or equivalent outstanding achievements. Experience leading teams as a Senior Engineer or Tech Lead (e.g., teams of 3+ members).

Technical Expertise

Deep expertise and large-scale development experience in at least two of the following stacks: Spring (Java or Kotlin) Vue.js / Nuxt.js / Quasar Go C# (.NET, ASP.NET) Advanced knowledge and hands-on experience with at least one cloud platform (AWS, GCP, or Azure), including infrastructure design and IaC (Terraform/OpenTofu).

Architecture

Experience designing modern architectures such as microservices, distributed systems, or event- driven architectures (EDA), with the ability to clearly explain design decisions. Strong foundational knowledge of computer science, operating systems, and the SDLC.

Communication

Ability to communicate technically in English within a multinational team (reading and writing required; speaking is a plus).

Preferred Qualifications

Experience developing financial systems or working in the FinTech domain. Experience with large-scale enterprise system development. Consulting-style experience in upstream phases, proposing technical solutions based on deep understanding of client challenges. Experience with high-security requirements typical of financial systems. Experience contributing from early product stages such as PoC or MVP, with a broad, business- level perspective. Experience introducing and operating agile methodologies (Scrum, Kanban).

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Ideal Candidate Profile

Continuously pursues optimal technical solutions and takes responsibility not only for code quality but also for business impact. Understands both the benefits and risks of Generative AI and actively applies it within projects and the organization. Willingly shares knowledge and supports the growth of mid-level engineers as a trusted team pillar. Remains calm and resilient when facing complex technical challenges or changing business requirements. Collaborates effectively with team members from diverse cultures and backgrounds. Values teamwork and demonstrates strong communication skills.

Example Projects

Public Financial APIs for Third Parties Frontend: TypeScript / Angular / Ionic Backend: Go, Kotlin (Spring)

Auth: OAuth 2.0, OpenID Connect, FAPI

In-house Payment Platform for Retail Cashless Transformation

Backend: Go, Java

Infrastructure: GCP, microservices, Kubernetes (GKE)

Online Financial Services for Major Financial Institutions

Frontend: TypeScript / Vue.js Backend: C# (.NET Core, ASP.NET)

Auth: OAuth 2.0

Core Banking System Modernization

Backend: Java / Kotlin (Spring) Infrastructure: Azure & GCP (multi-cloud)

Location & Work Style

Office: Edomi-zaka Mori Building 8F, 4-1-40 Toranomon, Minato-ku, Tokyo Work Style: Hybrid (office or remote, depending on project)

Office Attendance Policy: - First week after joining: Daily office attendance - Weeks 2–4: At least once per week - After week 4: Hybrid (project-dependent)

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Compensation & Benefits

Annual Salary: JPY 9,000,000 – 15,000,000 Monthly Salary: JPY 750,000 – 1,250,000 (includes 45 hours of fixed overtime) Additional overtime, holiday, and late-night work paid according to law. Trial Period: 3 months (no change in conditions) Working Hours: Flextime system (no core hours) Salary Review: Twice a year (based on performance and evaluation) Bonuses: None

Benefits

Social insurance (health, pension, employment, workers’ compensation) Commuting expenses covered Certification and learning support Book purchase support and optimal device provision Parental, caregiver, marriage, and maternity leave Summer vacation (3 days), year-end & New Year holidays, and additional sick leave

Why Join LiNKX

Significant technical autonomy in architecture and technology selection. Opportunity to tackle some of the most complex challenges in the FinTech domain using modern technologies. Clear, expertise-based career paths (Tech Lead, Principal Engineer, etc.) with competitive compensation. Deep involvement from requirement definition through design, enabling real business impact. Daily collaboration with a truly global engineering team representing over 25 nationalities.

Selection Process

Casual interview (optional) First interview (online) Second interview (online technical test) Final interview (on-site at our office)

Company Information

Founded: July 15, 2020 CEO: Mohamed Osamnia Employees: 100 (as of September 1, 2025) Capital: JPY 8.44 billion (including surplus) Website: https://www.linkx.dev/company

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