Software Engineer, Client Work

Business overview

Luxar is a company that is launching multiple businesses centered on AI. The same team works to support client companies' AI utilization and product development, as well as to create and grow our own products.

Even in the management of the company itself, we share the work with AI agents. We try out everything from research, requirements definition, design, implementation, and document creation in our daily work, and pass on the methods we found useful to the next job. People are responsible for deciding what to make and what not to make, forming relationships with others, reading the constraints of the site, and having ultimate responsibility for the quality of the experience.

What this business does

AI introduction and development support is a business in which we bring in the AI-native processes that we have honed through our own product creation and undertake everything from PoC to full-scale development, from requirement definition to verification.

While going back and forth between PoC design and development, UX research, and requirements definition, we organize what to create and how to verify it, and accompany you until it can be verified.

We bring the development methods we tried earlier with our own products to support, and bring the knowledge gained through support back to the creation of the next product.

What you will do

The scope of your initial assignment will be determined through an interview based on your experience and desired involvement from the job descriptions below.

1. We go to the client's site and create something that works from requirements and designs. Don't end with a prototype, raise the quality to a level that can be used in business.
2. Work together with other companies' development teams. Go through the code review, design agreement, and handover according to the other party's method of proceeding.
3. Work on multiple client projects in parallel and maintain quality while switching priorities and contexts.
4. Full stack + AI implementation (LLM, agent, RAG). Responsible for everything from design to implementation and robustness.
5. Train the harness to hand over work to AI agents. Each time you make one, you leave a pattern in the shape of the next one becoming faster.

What success looks like

• I can handle everything from listening to the work flow to moving things by myself.
• The products we create are not just prototypes, but are used in actual work.
• In addition to the code, we still have the molds to quickly create the next one.

Experience

Who we are looking for

• Someone who can not only produce a working prototype, but also produce a quality that can be operated by teams from other companies.
• A person who can create a design agreement with the PM and client without leaving ambiguity in requirements unaddressed.
• Someone who can handle receiving and returning reviews as part of the implementation.
• People who choose technology based on the experience used in their work, without aiming for AI/LLM.
• A person who can maintain the basis for judgment even in multiple cases and make it a form that can be passed on.

Experience and career path

You will gain experience in creating design agreements with teams from other companies, raising prototypes to GA quality, and going through operations and handover. There are ways to expand your role to technology lead, project lead, and business responsibility for AI introduction and development support.

Luxar is in the early stages of its founding, and rather than joining an already established organization, we are at the stage where we are creating the business process and company structure on the job. Successful decisions and procedures are not kept privately, but are preserved as skills and documents. Therefore, in addition to practical work in the area in which you are responsible, you will gain experience in creating a method to run a business with a small number of people and an AI agent.

Our primary engagement models are full-time employment at the company’s core and project-based contracting that brings specialist expertise. Depending on the role, co-founder, partner, or director arrangements may also be possible. Expanded responsibility is not an automatic promotion; we decide it together based on the work undertaken and the state of the business.

Development environment

In the implementation, we use Claude Code and Codex depending on the role. We combine Superpowers, Product Management plugins, and our own Skills to handle requirements, planning, testing, reviews, and completion confirmation in the same flow.

The Source of Truth for the task is Linear.claude-auto / codex-autoLabel issues are executed by GitHub Actions, and PRs are reviewed by AI. People make merge decisions rather than manually running the entire implementation process. Parallel work is divided into git worktrees, and this site is configured to be exported to Cloudflare Pages.

To work side-by-side with the client's existing team, leave requirements and design agreements in the repository and include review and handoff as a development completion condition. We check product-specific languages, frameworks, and clouds on a case-by-case basis.

Ways to work with us

• Full-time employeeWorking full time to create the core of Luxar.
• Independent contractorBring specialist expertise to individual projects.

Our job is not to end with a prototype, but to bring it up to GA quality that can be used in business. There are two levels of employment (core = full-time employees/spot = outsourced work). First of all, we are also looking for core candidates who are ready to handle projects.

Job details

Engagement type

Full-time / Contract

Trial period

Yes (duration to be discussed)

Expected annual compensation

7 million to 15 million yen

Location

Remote-first, with in-person work when needed.

Availability

To be discussed

Selection

Casual interview, interview, paid trial work, job offer

Selection process

1. 01Introductory conversationFirst, let's talk about what you want to do and how you want to be involved.
2. 02InterviewWe align your experience with the role you want to take on at Luxar.
3. 03Paid trial projectWork on a topic close to the actual role so we can understand how we work together. The trial project is paid.
4. 04OfferCheck and decide on roles, involvement, and conditions.

Why this role matters

• Rather than limiting the work of a software engineer (support business) to just one part of the process, we handle everything from decision-making to implementation and review of AI introduction and development support.
• The processes that can be passed on to agents, such as investigation, organization, generation, and implementation, are passed on to agents, and people spend their time asking questions, coming to an agreement with the other party, and determining the final quality.
• At a company in its early stages, we not only finish the task at hand, but also leave it as a procedure that can be used by the next person and the next project. Regular employees work at the core of the company, while outsourced employees bring their expertise to projects. The path to co-founding and business responsibility will be discussed individually depending on the job type and business status.