Full-Stack Engineer

Founding builder on our 0→1 unit — turning enterprise voice problems into shipped products on top of the OneInbox platform.

About OneInbox

We're putting voice at the heart of how enterprises actually run.
We're the production-grade voice AI platform built for Japan and Asia-Pacific.
We're handling millions of real calls every month — in Japanese, English, Hindi, and Arabic — for banks, real estate firms, and government services.
Try OneInbox today.

We've earned the right to make a bigger bet on top of our core platform — and we need a builder who can run with it.
Enterprise voice has more unsolved problems than our roadmap can cover. This role exists to find and ship the next one.
This is the closest thing to a founding engineer seat without leaving the OneInbox platform behind you.

Sit in customer conversations alongside the founders to understand which problem we're betting on next.
Spin up a clean technical foundation on top of OneInbox's voice AI stack.
Ship a working prototype to a real customer within the first month.

Own the end-to-end stack — backend, frontend, integrations, deploy.
Run weekly customer feedback loops and turn them into shipped iterations.
Stand up the basics: telemetry, on-call coverage, deploy pipeline, error budgets.

Convert the prototype into a product the customer actively pays for.
Define which parts of the new unit live on the core OneInbox platform and which fork.
Help hire the next two engineers on the 0→1 team.

3–6 years of full-stack experience — backend, frontend, and infra you've actually shipped.
Comfortable picking up a new system, reading docs, and shipping the same day.
Strong product instinct — you build for the outcome, not the spec.
You want to be a CTO or founder eventually, and you understand the path runs through building real things for real customers.
Bonus: experience with voice AI, telephony, real-time systems, or LLM pipelines.

Generational impact: build the voice layer that every APAC enterprise eventually runs on.
Ownership culture: you'll work close to the founders and ship in days, not quarters.
Kind, high-bar team: senior operators who've built and led at scaled companies — and are easy to work with.
Strong backing: institutional investors and committed enterprise customers from day one.

Real ownership: competitive salary and meaningful equity for early team members.
Health coverage: medical, dental, and vision for you and your dependents.
Team time: regular in-person off-sites across Tokyo, Singapore, Dubai, and Bengaluru.
Flexible time off: take what you need, when you need it.
Learning budget: dedicated annual L&D, plus conference and travel support.
Daily essentials: catered meals on office days, commuter support, and wellness benefits.