Backend Engineer (Spring Boot, 5+ yrs)

About us OhMyHotel is a Supplier Architecture Company that connects hotel inventory across Japan, Korea, and Southeast Asia via direct contracts, CMS, and wholesalers. We are heading toward Top-3 OTA status in Japan and aggressive B2C expansion. Our CTO Office team adopts Claude Code and other AI agents as everyday development partners. About the role You will pair with AI agents to build the core backend behind OhMyHotel's inventory, pricing, reservations, and settlement systems - and help drive AI Transformation (AX) across the whole company, not just engineering. Key responsibilities Design and implement new APIs and domain services in OhMyHotel's core backend (inventory, pricing, reservations, payments, settlement).
Build integrations with external systems (OTAs, CMS, channel managers, PMS, payment gateways) - and guarantee concurrency and correctness.
Incrementally migrate the accumulated legacy backend to the standard stack (Spring Boot 4.x + CQRS + TDD).
Use AI agents t...