Senior Backend Engineer - Node.js, AWS, and Flutter - Long-term, Japanese product team

We are a Japanese software development company building web and mobile products for clients in Japan. We are opening our first engineering roles outside Japan and looking for one senior backend engineer who can also work on mobile. Our working language is English. You do not need to speak Japanese. OUR STACK Node.js and AWS for the backend and infrastructure. Flutter for mobile. WHAT YOU WILL DO - Design, build and operate our Node.js backend services and APIs - Own our AWS infrastructure: deployment, monitoring, cost, reliability - Contribute to the Flutter mobile apps that consume those APIs - Work directly with our product manager in Tokyo, with no layers in between - Own features end to end: clarify the requirement, estimate, build, test, ship - Review other engineers' code as the team grows WHAT WE ARE LOOKING FOR - 5+ years of professional software engineering, at least 3 of them on backend - Strong Node.js and TypeScript. Production services you designed and operated, not just endpoints you added - Solid AWS. You should be comfortable owning deployment, monitoring and incident response without waiting for someone else - Working knowledge of Flutter. You do not need to be a mobile specialist, but you should be able to build a screen and debug the client side of your own API - Comfortable working from written specs in English, and comfortable asking questions when a spec is unclear - Based in Malaysia, Singapore, or another location within 2 hours of JST. We are UTC+9 HOW WE WORK - Async first. Written communication over meetings - One 30-minute sync per week, in your afternoon - We care more about how you handle ambiguity and bad news than about how fast you type ENGAGEMENT - We start with one small paid trial task, roughly 20 hours over one week. This is real work from a real project, not a take-home test - If it goes well, we move to an ongoing engagement at up to full-time capacity. Long term. We are building a team, not filling a gap PLEASE ANSWER THESE IN YOUR PROPOSAL Proposals that skip these will not be reviewed. 1. Describe one backend service you designed and operated. What was the traffic, what was the AWS architecture, and what broke in production? 2. A client sends you a one-paragraph spec for a new screen. It does not say what should happen when the API call fails. What do you do, and when do you do it? 3. Tell me about a time you knew a deadline would slip. When did you tell the client, and what exactly did you say? 4. How much Flutter have you actually written? Be honest. A link is better than a claim. ABOUT US Hajimari Inc, Tokyo, Japan. We build web and mobile applications on contract. We already work with an offshore team in Vietnam and are now expanding.