C# and ASP.NET Engineer / English Speaking

Position Overview

As a Backend Engineer, you will design, develop, and operate  Cloud and our next-generation energy software platform.

You will collaborate with an international engineering team where English is the primary working language. Japanese language proficiency is not required.

Responsibilities

• Design, develop, and maintain Cloud and related products
• Participate in the full software development lifecycle, including requirements gathering, architecture, implementation, testing, and deployment
• Improve existing systems through performance optimization and technical debt reduction
• Design scalable and reliable backend architectures
• Build, operate, and optimize cloud infrastructure on Microsoft Azure
• Improve development workflows through automation and engineering best practices
• Conduct code reviews and provide technical support to teammates

Required Qualifications

• Professional experience developing web applications using C# and ASP.NET Core
• Experience designing and implementing REST APIs
• Experience working with relational databases such as SQL Server
• Experience designing databases using Entity Framework Core or similar ORM frameworks
• Solid understanding of object-oriented programming and software design patterns
• Experience developing applications on cloud platforms such as Microsoft Azure
• Experience writing automated tests
• Experience working in Agile development environments
• Strong English communication skills for collaborating within an engineering team
• Japanese language skills are not required

Preferred Qualifications

• Experience designing and managing Microsoft Azure infrastructure
• Experience using Azure DevOps
• Knowledge of Domain-Driven Design (DDD), Clean Architecture, or CQRS
• Frontend development experience using React or similar frameworks
• Ability to independently research technical documentation written in English

Ideal Candidate

We are looking for someone who:

• Is passionate about transforming the energy industry through technology
• Enjoys tackling new challenges and exploring unfamiliar domains
• Takes ownership of problems and proactively drives solutions
• Thrives in a fast-paced startup environment
• Values collaboration, continuous learning, and engineering excellence

Technology Stack

Backend

• C#
• ASP.NET Core
• Entity Framework Core
• REST API
• xUnit

Frontend

• TypeScript
• React
• Vite
• Vitest
• React Testing Library

Cloud & Infrastructure

• Microsoft Azure
• Azure SQL Database
• Azure DevOps

Development Tools

• GitHub Enterprise
• Visual Studio 2026
• Microsoft Teams