Mid or Higher - Full Stack Engineer

About Us

KATIX is a fast-growing vehicle auction platform built for transparency and trust. We connect buyers and sellers of motorcycles and cars through a modern digital marketplace — and we're expanding. Real estate is next, and we're building the team that will take us there.

We're a diverse, product-focused team of about 60 people, with an average age of 27 and over 50% women. We care about building great software and we care about the people who build it.

The Role

We're looking for a full stack engineer with strong web engineering foundations to join our product team. You'll work on a modern TypeScript/Next.js monolith used by thousands of users every day, and you'll contribute across the stack — from buyer flows and auction tooling to internal dashboards and infrastructure.

This is not a role where you'll wait for tickets. We expect engineers at this level to bring ideas, push back when something isn't right, and take real ownership of what they build. Over time, there's a clear path toward tech lead and senior engineering roles as we scale.

We're looking for someone who has genuinely looked into KATIX, understands what we're building, and wants to be part of it. If you believe in what we're doing and want to grow with us, we want to hear from you.

What You'll Work On

Our main product is a vehicle sales platform — auctions, escrow, AI integrations, user onboarding, and internal tooling — built as a large TypeScript/Next.js monolith. You'll work deep inside this codebase, contributing across:

• Frontend features using Next.js (App Router) and TypeScript
• Backend logic via API routes, server actions, and shared packages
• System design, database schema, and feature planning
• AWS infrastructure, Docker, ECS, and GitHub Actions deployments
• Code review, testing, and CI pipeline reliability
• Team planning, standups, and retrospectives

What We're Looking For

Required

• 5 or more years of professional web engineering experience
• Strong full-stack background — comfortable with both frontend and backend work
• Solid understanding of web architecture, system design, and data modeling
• Experience with modern web frameworks (React, Vue, or similar)
• Exposure to backend development, API design, and relational databases
• Experience with cloud infrastructure — AWS, Docker, or similar
• Experience mentoring others or leading small projects
• Comfortable working in a Scrum or Agile team
• Conversational Japanese (you'll be working with a Japanese-speaking team)

Nice to Have

• Hands-on experience with Next.js, TypeScript, or Prisma
• Experience with ECS, ECR, or other AWS services beyond basics
• A track record of improving engineering quality across a team — code standards, review culture, testing
• Experience at a product-focused startup or fast-growth environment

The kind of engineer we're excited about

You care about user experience and business outcomes, not just technical elegance. You can engage confidently in design discussions, push back on ideas (including your own), and adapt when you get good feedback. You've built things you're proud of, and you can explain why the decisions you made were the right ones — or what you'd do differently now.

Why Join Us?

• You'll ship real features from day one — no backlog purgatory
• You'll work in a clean, modern codebase with a collaborative team that actively mentors and reviews
• Clear growth path into tech lead and senior engineering roles
• Help shape how we build software as we scale toward our next phase of growth
• A diverse, friendly team with a strong product culture

Benefits

• Transparent compensation table with performance reviews every 6 months
• Two annual performance bonuses
• Housing allowance for those living near Shibuya
• Dedicated budget for learning, certifications, and study
• One or more remote work days per week (after the first 6 months)

How to Apply

You don't need a perfect resume or a portfolio full of side projects. What we do want to see is that you've looked into KATIX, that you understand what we're building, and that you're genuinely excited about being part of it.

Tell us about yourself, what you've built, and why KATIX. We'd love to hear from you.