About Yejua

The era of merely consuming AI is over.
We design and provide it.

A developer's eye, a seller's scars

Not a coding vendor

Built on two decades of engineering depth, and on the frustrations we met selling online ourselves — which is what the automation was written to solve.

Tools go wrong when you don't know the floor

Subtract fees and international shipping and the margin disappears. Detail pages have to be rebuilt for every language. Order status is never where the API docs say it is. None of that reaches your design unless you have sold something yourself.

We don't build what we wouldn't use

Every Yejua product runs on our own operations first. The commerce automation drives our own store; the AI Gateway carries every LLM call across our products. We verify before we sell.

CTO Leadership

We tell you who builds it

The largest unknown in outsourcing is who actually writes the code. At Yejua the founder designs and implements it.

C

Choi Hyungjun

Founder · CTO

Exp.
20+ years, full-stack
Role
Architecture · build · operations
Email
contact@sales-agent.kr

Nothing is handed down a chain

When sales takes the brief and passes it to a developer, requirements get translated twice and arrive bent. Here, one person's judgement runs from architecture through implementation, deployment and incident response. Decisions are fast, and what ships actually runs.

Track record

  • Enterprise systemsLed large-scale system design and build across multiple IT organisations, resolving technical debt and growing teams alongside it
  • Enterprise cloudOperated VM-based services on Microsoft Azure, built and migrated Azure SQL databases, and shipped generative image features on Azure OpenAI
  • Selling, first-handSold online directly, met the limits of sourcing, margin and inventory, and solved that stretch with automation
  • Own SaaS in productionBuilt and operates an LLM gateway and a line of agent and commerce products on AWS
ArchitectureReact · TypeScriptNode · PythonAWS · AzureLLM pipelinesn8n automationMariaDB · PostgreSQL
Milestones

How we got here

  1. Foundation years

    Two decades of full-stack engineering

    Twenty-plus years across IT projects — including Prime Information & Communications — leading system design and build, and accumulating the depth that shows up in architecture decisions today.

  2. 16 May 2025

    Yejua founded, and a turn as an online seller

    Alongside registering the business, we sold online ourselves. Running into the real limits of global sourcing, margin and inventory led directly to building automation tools, and to launching yejuamall.com, an AI-assisted Japan sourcing mall we still operate.

  3. April 2026 – present

    Into an AI agent ecosystem

    Agent development began in earnest in April 2026. We built the AI Gateway on scalable infrastructure, released our own SaaS line-up, and delivered an advanced AI assessment simulation to an enterprise client.