Full Stack Engineer (Ruby on Rails & React/Vue)

Filled
March 5, 2026
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Job Description

Experience Required: 5+ years
Salary: Confidential (based on experience)
Notice Period: 15 Days
Shift: GMT+09:00 Asia/Chita (YAKT)
Opportunity Type: Remote
Placement Type: Full-Time Contract – 12 Months (40 hrs/week, 160 hrs/month)

Client: Social Chat Commerce Solution Provider (via Uplers)

About the Client

  • Ranked #1 on ProductHunt
  • Over 10,000 AI agents generated worldwide within months of launch
  • Product highlights:
    • Voice + chat hybrid widget
    • Smarter recommendation engine
    • Shopify integration
    • Monetization live with early ARR tracking strongly

Mission: Revolutionizing sales with Agentic Voice AI agents that close sales, not just answer questions. Agents provide live product recommendations, conversation analytics, and instant website scraping with zero setup.

Role Overview

As a Full Stack Engineer, you will:

  • Dive into global AI product development during the zero-to-one phase
  • Work directly with the CEO and core team from Japan
  • Build for global markets with AI-driven rapid iteration
  • Shape the future of sales technology from the ground up

Typical Day

  • 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: front-end interfaces, backend services, and data storage
  • Make system architecture decisions for scalability
  • Provide technical leadership through execution (no direct reports required)

Must-Have Skills

  • Backend: Go, Ruby on Rails, C#, Python
  • Frontend: React.js, Vue.js, Next.js, Remix
  • State Management: Jotai, Recoil, Zustand
  • Databases: PostgreSQL, NoSQL, Redis
  • Cloud: AWS / Google Cloud
  • Other: AI integration, distributed systems, microservices architecture, CI/CD, performance tuning, security, and production-level development

Preferred Experience

  • Server-side rendering / meta-frameworks
  • Observability tools (APM, distributed tracing)
  • High-availability systems & incident response
  • AI-assisted development workflows (Cursor, Windsurf, AI-enhanced IDEs)
  • Startup environment experience

What Makes You Stand Out

  • Full-stack developers who cross frontend/backend boundaries
  • Engineers curious to implement new AI/LLM technologies
  • Startup-speed enthusiasts ready to push limits
  • Understanding that chatbots suck and aiming to build something impactful

Team & Culture

  • Small, 4-person technical team reporting directly to leadership
  • Rapid iteration focus – “Always Be Launching”
  • Autonomous execution expected
  • Participate in incident response & system maintenance
  • Japanese conversational skills welcome