Full Stack Engineer

Think Different. Build Different. Full Stack Engineer
#1 on ProductHunt. Over 10,000 AI agents generated worldwide within months of launch – that’s our voice AI agent platform Omakase.ai. The product has evolved with major updates including a voice+chat hybrid widget, a smarter recommendation engine, and Shopify integration. Monetization is live, and early ARR is tracking strongly. We’re confident in the trajectory for global impact — that’s why we’re hiring elite engineers to join us from Japan. Let’s scale a Japanese-born AI product globally!
What We Do
We’re revolutionizing sales with Omakase.ai – because chatbots just answer questions, but our Agentic Voice AI agents actually close sales.
Our voice-powered sales agents behave like real sales reps – persuasive, helpful, and always on-brand. They provide live product recommendations during conversations, conversation analytics to understand customer behavior, and a smarter scraping engine that learns any website instantly with zero setup required.
As a Full Stack Engineer
You’ll dive into global AI product development during our zero-to-one phase. You’ll work directly with our CEO and core team from Japan while building for global markets, experiencing AI-driven development with rapid iteration from concept to release. This is your chance to shape the future of sales technology from the ground up in an international work environment that welcomes both Japanese and non-Japanese speakers.
Your Typical Day With Us
Take full technical ownership of a key product domain (integration systems, data pipeline architecture, conversational AI engine, or client application layer)
Lead end-to-end full-stack development, from front-end interfaces to backend services and data storage
Make system architecture decisions designed to scale to millions of concurrent users
Provide technical leadership through expertise and execution, without direct reports
What you'll Need
9+ years building production software systems
5+ years building scalable backend services in production environments with Go, plus working knowledge of Ruby on Rails. Equivalent experience with other backend technologies (Python, C#, Node.js, etc.) will also be considered
3+ years building modern web applications with React or Vue
Experience with distributed systems design and microservices architecture
Global state management in complex frontend applications
Production database optimization and query performance tuning
CI/CD pipeline design and automated testing strategies
Application monitoring, logging, and performance optimization
Security implementation across authentication, authorization, and data protection
Experience shipping features that measurably impacted business metrics
Technical Environment
Backend: Go microservices with Rails BFF layer
Frontend: React with TypeScript
Data: PostgreSQL with Redis caching
Infrastructure: Cloud-native deployment with container orchestration
Development: GitHub-based workflows with automated deployment
Preferred Experience
Server-side rendering or modern meta-frameworks (Remix, Next.js)
Specific state management libraries (Jotai, Zustand, Recoil)
Observability tools (application performance monitoring, distributed tracing)
High-availability system operations and incident response
Experience with AI-assisted development workflows and modern tooling (Cursor, Windsurf, AI-enhanced IDEs)
Startup work experience
What makes you stand out
Engineers who understand that chatbots suck and want to build something that actually works
Full-stack developers who can cross frontend/backend boundaries and autonomously drive product growth
Builders with curiosity and drive to immediately implement new AI/LLM technologies into products
Engineers who thrive on startup speed and can push beyond limits
Team & Culture
4-person technical team reporting directly to leadership
"Always Be Launching" - rapid iteration with production focus
Autonomous execution expected - minimal technical guidance provided
Participate in incident response and system maintenance alongside founding team, transitioning to structured on-call rotation as we grow
Japanese conversational skills welcome for team collaborati
Interview Process
Application screening → HR interview → Technical interview → CEO interview → Panel interview → Offer
Now is the time to take your code to the world
We're going after the world now, not "someday."
We're excited to create an incredible future with those who share our vibe.
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For applicants via our CEO Masa Shimizu’s X account:
Please note that if we receive a high number of applications, we may limit the number of candidates selected for an interview with Masa Shimizu as part of the screening process. We appreciate your understanding and thank you for your interest.