About Reaktor Japan

Reaktor is a global technology consulting firm originating from Finland.

Through a flat organisational culture typical of the Nordics, consultants with advanced specialist skills and know-how collaborate as a team, autonomously delivering results that create value for clients and users.

We combine digital x design x business and provide consulting services that lead clients' digital services to success.

Our Work

• Games & Entertainment: Supporting Supercell's global service "Supercell ID". We develop native apps and SDKs that support tens of millions of players, and take responsibility through to integration across multiple games, tackling large-scale, high-quality product development.

• Global Retail: Building scalable platforms that support Adidas's digital experiences.

• Aviation & Infrastructure: Combining UX and technology to redefine Finnair's customer journey.

• Domestic Projects in Japan: Working alongside major domestic companies, we are renewing legacy environments into modern architectures and leading the transformation towards an agile organisational culture.

👉 For more details, please see Reaktor Work (case studies)

Background to the Role

Japan is home to many companies that create games loved by players around the world. To bring games to many people over the long term, various systems that support the game itself are needed, not just the game.

Reaktor has so far worked with overseas game companies to build important systems that support games, such as account infrastructure, data and operations. We want to apply that experience and expertise in the Japanese game industry as well.

To do so, we need people who not only have technical strength, but who face clients directly, think through challenges together, and move projects forward while building relationships of trust.

This role is for someone who leads a team as an engineer, becomes a trusted partner to clients, and helps expand Reaktor's games business together with us.

About This Position

What is especially expected of this position is not simply hands-on implementation. You will take on the role of a member of the client's team, leading product development to success.

You will lead client projects from technical, delivery and business perspectives, set direction with the client, lead the team, and take part in development hands-on yourself. You will stand at the intersection of technology, business and product, turning client needs into concrete actions.

In addition, making the value our work creates visible to clients is an important part of this role. Understanding what matters for the client's business, checking that the team is working on problems of real value, and building trust and reliable delivery will lead to deeper, long-term partnerships.

Specifically, you will take on the following responsibilities.

• Lead on technical matters as a senior technical adviser to both the client and your own team

• Rather than waiting for the client to tell you "what to build", identify challenges early and lead towards solutions

• Build relationships with various stakeholders within the client organisation and explain what business value our work leads to

• As a member of the team, take part in designing and implementing features including front end, back end and infrastructure

• Work with both technical and business stakeholders on the client side, drive decisions and move projects forward

• Take part as a technical adviser in initial sales activities with new clients

• Create effective development approaches suited to the team and client, incorporating agile, AI tools and user-centred approaches, and improve them continuously

Profile We Are Looking For

This position requires ownership of outcomes. When something is ambiguous, stalled or not going well, you need the ability to act yourself and move the situation forward, rather than waiting for clearer instructions, decisions from above or someone else to resolve it.

Working with Clients

• When requirements or requests are ambiguous, do not guess or wait; check directly with the client

• Quickly grasp the situation, propose clear next steps and lead, then build agreement through dialogue with the client

• Build trust with the client, including its senior management, and become an adviser they rely on

• Understand the client's business well, define what "success" means in line with its business metrics and processes, and move the project towards it

Working with the Team

• Give feedback directly to the person concerned, and sincerely engage with feedback you receive, turning it into action

• Take ownership of the team's success, act on your own initiative and lead; when something is needed, step up and make sure nothing is left falling through the cracks

• Contribute to building a team that clients trust as one team of specialists, rather than a collection of individuals

• If something about scope, planning or quality feels wrong, speak up early

As an Individual

• Share Reaktor's aims and devote your own efforts to realising them

• One of Reaktor's mottos is "Do first, apologize later". Rather than stalling while waiting for a perfect plan, act first and learn from there

• Hold both humility to learn from anyone and the confidence to set clear direction when needed

• Have a professional network in Japan and be able to take part in sales activities with your own perspective

Experience

• Roughly 10+ years of practical experience in a related field. We consider this a guideline for succeeding in this position

• Experience leading a team and managing client relationships (project, account or delivery management, etc.)

• Especially welcome: Experience in the games industry, game studios, game platforms, or large-scale consumer services. Not mandatory, but this position is an important role in growing our business in the games industry

Technology

Depending on project needs, you will work across back end, front end, DevOps and other areas without drawing boundaries. We are not looking for one engineer who is familiar with every area; we value the team as a whole having the skills it needs. Please tell us which areas you are strong in and which you are not.

• Deep specialist expertise in at least one of front end, back end or infrastructure, and the ability to work across the others

• Ability to build new back-end services or change CI/CD pipelines as needed

• Experience working with databases such as PostgreSQL

• Practical experience in at least one common server-side language. Many projects use TypeScript/JavaScript and Node.js, and we also use Golang, Python, Java/Scala/Kotlin and others

• Strength in at least one client-side language or framework. For web we use TypeScript/React; for mobile we use Swift, Kotlin, React Native and others

• Ability to understand what good code is from both theory and experience, and to build high-quality systems

• Routinely use AI tools in everyday software development, with your own view of where they help and where they do not. Even when using AI, you take responsibility for the final deliverables

Recent Main Tech Stack

TypeScript, React, Node.js, Golang, Python, Swift (UIKit/SwiftUI), PostgreSQL, Redis, AWS/Azure/GCP, Terraform, Docker, GitHub

Desirable Skills and Experience

Experience with functional programming, ability to design complex systems, and experience developing and operating large-scale applications.

Languages

• Japanese: Native/Bilingual

• English: Business level

Location

Basically work at the Ebisu office or at client sites. Remote work and business travel are also available as needed.

Company Culture and Working Environment

• Flat and transparent organisation: An organisation with minimal hierarchy, where decision-making processes and business conditions are open. An environment where free exchange of opinions is possible regardless of rank is in place.

• Autonomous teams built on "freedom and responsibility": There is considerable latitude in how we work with clients and how teams operate, and responsibility for the results. Approach, technology and development methods are chosen by the team together with the client.

• A team that supports your success: Experienced, candid and considerate members gather together. The Tokyo office currently has members from nine countries.

• An environment to grow: In addition to internal training and community events, there is a global network connecting you with Reaktor members around the world who have experienced similar challenges.

• Good work with good colleagues: There is an excellent software development culture that respects technical expertise. We were certified as a Great Place To Work in 2023, 2024 and 2025.

Benefits

• Comprehensive welfare plan from the Kanto IT Software Health Insurance Society

• 20 days of paid annual leave, with active encouragement to take it

• Multilingual counselling provided by Tokyo Mental Health

• High-spec laptop and smartphone of your choice, plus tools necessary for work

Salary

Discussed at interview, taking into account experience and skills